
How do you avoid bugs in stored food on a boat? Step one: You have to be fanatical about avoiding “critters” – cockroaches, ants, weevils and other bugs! Some of the critters will come right from the store, while others will come aboard at the dock. I was able to avoid any major infestations by being constantly vigilant and following these rules.
- Never take cardboard on board the boat if you can help it. All sorts of things lurk in cardboard, even in very modern and clean supermarkets. Get rid of it on the dock or the beach whenever possible if you really want to avoid bugs in stored food. For packages that don’t have an inner liner (such as pasta), don’t even set the box down in the boat. Pour the contents into a Ziploc or plastic canister and then toss the cardboard box onto the dock or dinghy immediately. You can read more about ways we avoiding cardboard in Getting Rid of Cardboard and Getting Rid of Cardboard Wine Boxes.
- Clean up any spills as soon as you find them and always be looking. Any sort of spilled food will attract ants and roaches and the problem will only grow the longer it’s left. Messes do not clean themselves up — even though it may not be convenient, you have to clean things up when you find a problem. And while it’s not part of food storage, keep the “gap” between the stove and counter clean.
- Wash produce immediately when you bring it on board. Use one capful of bleach in 1 to 2 gallons of water and start with the foods that have the least dirt on them, such as lettuce. If the water gets too dirty, change it. Thoroughly swish produce around in the bleach water and then let it dry before putting it away. This is important both for getting rid of bugs and also preventing food-borne illness.
- Wash cans of fruit, vegetables and drinks if they look at all dirty — that dirt can carry a lot of tiny critters. Before getting paper labels wet, be sure to mark the top of the can with the contents, using a permanent marker.
- Keep bottles of sugary items like honey and syrup inside sealed double plastic bags in case they leak or break — anything sugary is a huge attractant for ants. (NOTE: I also double bag anything else that would be a nasty mess if it broke, like oil.) This is hugely important to avoid bugs in stored food.
- Put a bay leaf in every bag of flour and any mixes that contain flour to discourage weevils. Further, don’t buy flour that looks like it may have been sitting on the shelf for a while, or from open bins — both are much more likely to have weevils in them. If you have no option but to buy suspicious flour, put it in a pan and bake it at your oven’s lowest setting (around 200 degrees F) for 30 minutes before putting it into a storage container, or freeze it for at least 24 hours (sometimes you can use the freezer at a marina restaurant) — and be sure to stick bay leaves in it.
- Put a whole clove in every locker to drive ants away. You can also use a sprinkling of ground cloves or a drop of clove oil. Refresh every 3 months. You’ll smell the cloves for the first few hours, but the scent will quickly wear away, although the ants will still avoid the area.
- Put an ant trap and cockroach trap in every locker and replace at the recommended interval. If you can’t find traps where you are, a mixture of boric acid (usually available at pharmacies) and powdered creamer in a bottle cap works well against both ants and roaches — replace it every 2 months.
- Address any infestations immediately. They won’t go away on their own; they’ll just get worse and worse. Totally clean out any lockers with problems — scrub the inside with a bleach solution and also wash the contents with a bleach solution. If the critters have gotten in any food, throw it out — off the boat, not just in a trash bag on the boat. (UPDATE: Read more here about how we dealt with an ant infestation and two great products.)
- A bug bomb may be the only solution for a large infestation. It’s a huge amount of work to remove all the dishes, pans and cooking utensils, cover the food preparation surfaces, open all lockers and then get out for the required time and clean up and replace items afterwards. It’s a lot easier to prevent an infestation in the first place or deal with it when it’s small.
More on Storing Food
Simplify meal prep on board with proven strategies for provisioning, maximizing fridge space, and cooking delicious meals aboard your boat.

Carolyn Shearlock has lived aboard full-time for 17 years, splitting her time between a Tayana 37 monohull and a Gemini 105 catamaran. She’s cruised over 14,000 miles, from Pacific Mexico and Central America to Florida and the Bahamas, gaining firsthand experience with the joys and challenges of life on the water.
Through The Boat Galley, Carolyn has helped thousands of people explore, prepare for, and enjoy life afloat. She shares her expertise as an instructor at Cruisers University, in leading boating publications, and through her bestselling book, The Boat Galley Cookbook. She is passionate about helping others embark on their liveaboard journey—making life on the water simpler, safer, and more enjoyable.
MaryJo says
I’m confused about the whole cardboard thing. Everybody says “don’t bring cardboard on the boat”, but lots of things, like facial tissues and boxed wine come in cardboard. I can’t take those items out of their boxes. Please clarify.
Thanks!
Carolyn Shearlock says
Good point, MaryJo! I’d phrase it more as “get rid of all the cardboard you can” before bringing things on the boat. For example, cereal boxes usually have a plastic bag inside the box. I trash the box on the dock and just take the bag aboard. We tended to just use a bit of toilet paper instead of bringing Kleenex boxes on the boat. Sometimes wine boxes have a inner bladder, so you can leave the box behind; sometimes they are a Tetra Pak without one and you can’t.
So yes, we did have some cardboard on the boat — I can’t imagine trying to leave the cardboard roll out of the toilet paper, for example!
But the more cardboard that you can prevent from ever coming aboard, the better. And some has to come onboard, but then I can quickly transfer the contents to a plastic bag or a “Tupperware” — spaghetti and other pasta are good examples. Then I get rid of the box as fast as possible.
The other advantage of getting rid of the boxes (in addition to the whole pest control issue) is that they usually take up far more space than the contents. And I’ve never known a boat where space wasn’t at a premium!
Thanks for the question!
-C
UPDATE: I’ve written a more in-depth article on this called “Getting Rid of Cardboard” that details more of our techniques.
Heather says
They now have toilet paper rolls that don’t have the cardboard in them. I think it’s Cottenell that has this nice feature now.
Alexandra B says
I am interested to know whether cardboard should be kept off the boat at all times or whether it is only when you’re in the tropics?
If I have taken cardboard onto the boat that has originated in cooler climates will it be ok or is all cardboard a no-no?!
Thanks!
Carolyn Shearlock says
Good question, Alexandra . . .
There are definitely MORE bugs in the tropics, but you can get them wherever you are. And while there seems to be some controversy about exactly what bugs do and don’t come aboard in cardboard, and which ones just like to live in it or perhaps eat crumbs left on it once they’re aboard from other sources, I’ve just found that the less cardboard there is on the boat, the less trouble there is with bugs.
In cooler climates, I don’t have the trouble with cockroaches that I did in the tropics. But I have had ant infestations and also numerous spider nests — and the spiders, in particular, made the corners of cardboard boxes their home. Getting rid of the cardboard took away one of their hiding places, making it easier to discover a problem before it got out of hand.
Patty Alderson on Facebook says
Ooohhh, so timely! Saw one today….ewwwww! Thx for the hints!
John says
Flour sifters were invented to sift out the “big chunks” in flour, said “chunks” being weevils which had hatched from weevil eggs and grown.
Weevils and weevils eggs are on the wheat when it grows in the fields. Most of the weevils are removed during commercial grinding, but the (small) eggs are left behind, along with a bunch of other “insect parts” which is all legal (and harmless) within certain limits and has been fine and safe for the thousands of years people have ground wheat into flour.
Generally, if you want weevilless flour you need to use it not long after it is ground (a few months), OR put a piece of Dry Ice(R) in the storage container and seal it OR put a bay leaf in the sealed container OR use a flour sifter. Great-Grandma used a sifter, and it was safe.
Flour baked at 200* prior to storage may work, but I have no empirical knowledge to say either way. I suspect it may well work, though baking flour at 200* **may** give it a slight burnt flavor. (Baked goods even in a 375* oven seldom get to 200* before done.)
Sarah Hanson says
Hi Carolyn. We’re getting our boat ready for cruising, and I’m referring to your site several times a day as I provision and outfit her. I have a question about the bay leaf to prevent weevils: do you use one even in sweet things like cake mixes? Does the bay flavor get into the mix? Not sure I’d like it with chocolate!
Thanks so much for providing such a great service to other cruisers!
Carolyn Shearlock says
Quick answer . . . yep, I put bay leaves in everything that has flour — cake and brownie mixes, Bisquick, etc. For cake mixes, I put either the box or the inner bag (depending on how it’s packaged) in a larger Ziploc with a couple bay leaves just in the big Ziploc. In other words, I don’t take the cake mix out of its original package. For flour and Bisquick-type things, I put bay leaves in the canisters, too, when I open the package . . . but before it’s open, just in the Ziploc “over” bag.
Margaret McGovern says
Hi Carolyn,
I wanted to pass on something it has taken me three seasons to learn. We are in the Rio Dulce. The dish detergent here is terrible! Or maybe the water is extra hard. Either way, I have been going through a lot of detergent. Several squirts in a sink of warm water seems sudsy at first, but after just a few dishes the suds is gone. I finally changed my method and squirt the detergent directly on my yellow scrubber (LOVE the yellow scrubbers you recommended). I put a small amount of water in a bowl or glass in the sink and dip occasionally. One squirt can clean a whole sink of dishes with only a small amount of water, so this saves water, too.
Carolyn Shearlock says
Jim Allen sent this to me in a Facebook message:
Have to say one of the best things that I have purchased recently is the FoodSaver vacuum machine. Beside food I did my weekly pill containers and left them in the bathroom to expose them to a much steam and humidity possible. I just opened the third week and all the capsules were good and not soft and sticky. One thing I will do for the next month is use the gentle setting. A couple of the 2 part caps were actually pulled apart by the vacuum .
I was thinking about the posts about keeping bugs and moisture out of things like flour , sugar, etc.What about vacuum sealing them in small amounts equal to the average amount you typically use, say 2 cups for flour., 1 cup for sugar, Etc.. This would guarantee no bugs, no moisture problems, and allow easy storage!!
Glenn says
Thank you for the article will keep all this in mind. One thing I learned years ago when stationed in Florida was to take my cucumber peels and place them around the areas where I seen or think of a cockroach. With in just a few days never seen a cockroach again in our place. We ate a lot of salads so changing the peels every week or so kept those little buggers and the big ones away.
Becky Rains says
Hi Carolyn,
Have you ever used Fresh Cab, a rodent repellent? We have/had a mouse in the camper over the winter. We also have a boat we spend a little time on and know that is a potential problem as well. Thanks in advance, love the Boat Galley and your cookbook!
Carolyn Shearlock says
Have never heard of it — I’ll have to look it up!
Brenda Furry says
Fragrant cedar is toxic to small mammals (mice, rats) but safe for dogs, cats and humans. I fill old socks with a small amount of cedar pet-bed chips, and place them in all clothing and sail compartments, as well as under sinks. This worked well when we lived in the woods, and I haven’t seen sign of critters on the boat, yet.
Sailing Tiny Nical says
Found a maggot type critter in my plastic container of Citric Acid – how the? And of all places? Kitchen is spick and span now
The Boat Galley says
That’s certainly a new one!
Julia Weeks says
Possibly larvae of a pantry moth?
Rose-Mari Sephton says
Is it possible to post pictures of the inside of your cubbards, I realize it sounds silly but I want to be prepared for fitting out our boat. We will only be cruising in the waters off the coast of British Columbia.
Thanks so much for your info, I enjoy your articles.
Carolyn Shearlock says
Thanks for the idea! Every boat is different, but I certainly can post pics of mine.
Julia Weeks says
We discovered a pantry moth problem… not fun. Gross little maggot-like things. Thankfully, we had some things stored in lock n lock containers but we never had enough of those, so some things were in ziplock bags – had to get rid of those… But it appears that lock n lock did the job so we will be buying more of those when we can.
Anonymous says
Tyrone Gilbert
Anonymous says
We’ve seen an occasion roach this season and kept most cardboard off the boat. What do you use for that? And do you put anything in food areas (canned) or just in non food spaces? I found some boric acid tablets at the market here (Abacos) wasn’t sure where I could put them. TIA
The Boat Galley says
I definitely have used boric acid in food areas but make sure all my food is fully enclosed — but I do that anyway to keep bugs out. Boric acid is very mildly toxic to humans if eaten in more than trace amounts — you may vomit or get diarrhea, but no “major” side effects requiring hospitalization or causing death (of course, if you’re in poor health, side effects can be greater). You want to keep pets and small children away from it just due to their smaller size.
Jackie says
How do you put the boric acid in the food cupboard. Do you sprinkle it around, or have it in a open container.
Thanks, Jackie
Carolyn Shearlock says
Well, she had boric acid tablets. If you have liquid, you can mix it with powdered coffee creamer or peanut butter to make a paste and then fill bottle caps with it and put it in lockers. If you have powdered, mixing it with peanut butter or liquid milk is best to make a paste.
Anonymous says
The Boat Galley thanks I do keep all food enclosed too, think I’ll try those.
Sally says
Have you ever used glass mason jars to store flour items? Does this work or does it have to be plastic?
Carolyn Shearlock says
It all depends on whether you can secure the Mason jars so they won’t break. Be sure to put them in socks — it both helps protect against breakage AND is one should break, the broken glass is contained.
Verna says
With ant and roach traps you say every locker. Does this mean under the floor where only food is stored or ALL regardless? We have cedar “closets” so is that sufficient for keeping rodents out of those?
Thanks
Carolyn Shearlock says
I’ve had them nest in a locker that had no food in it, so we tend to keep them in most lockers. The cedar might be sufficient — I probably wouldn’t put the traps in those unless you see signs of a problem.