Bugs and Pests on Sailboats
01-04-14
“Build a boat, and every creature will want to come ”
Woody holding up the elusive rat onboard S/V Mothership
The Miserable Truth
If there’s one thing they never mention in those performative, sun-soaked YouTube videos and Instagram posts about sailing in the tropics… it’s the vermin. Flies, mosquitoes, ticks, wasps, ants, cockroaches, rats, and a biblical variety of God’s other tiny critters will try to make your boat their home. And in the process, they’ll sting you, bite you, drink your blood, and infest your floating paradise, potentially making life a misery.
If there’s one thing they never mention in those sun-soaked YouTube videos and Instagram posts - it’s the vermin.
Vermin, Disease, and a Dead Rat Behind the Speaker
And it’s not just annoying. In some parts of the world, this floating zoo becomes a genuine health hazard. Dengue fever, yellow fever, malaria, Japanese encephalitis, leptospirosis, and a long list of other diseases that sound like they’ve been cultivated in a Chinese lab.
Boats are vermin magnets. Give them half a chance and they’ll find the smallest crack, squeeze in, and breed a multi-generational colony.
Give them half a chance and they’ll find the smallest crack and squeeze in. Prevesa, Greece.
Toward the end of our circumnavigation, we sat in the cockpit one evening with other cruising parents, trading vermin stories over beers while swatting away wasps. We’d made a video of the time we were boarded by a rat in Spain years before we’d even left the Med. and apparently it was still doing the rounds five years later.
This particular rat stowed away one night in a marina and moved in like he owned the place. We tried traps. We tried peanut butter. We tried increasingly elaborate schemes involving buckets, pans, and eventually a borrowed Patterdale terrier , Oscar (a veteran rat assassin) from some cruising friends.
We tried increasingly elaborate schemes to catch the rat including a Patterdale terrier called Oscar. - Almerimar, Spain
Even Oscar didn’t work.
Eventually, the marina dosed the pontoon with poison, which DID work. But not before the damn thing crawled into an inaccessible crevice between the deck and headlining and died.
What followed was the unmistakable stench of rodent death wafting through the saloon and a week long bluebottle infestation. We finally retrieved it by removing the speaker and shoving a vacuum extension into the hole to suck out the rotting corpse, like some sort of twisted veterinary endoscopy.
We retrieved the rat with a vacuum extension, sucking out the rotting corpse, from behind the cockpit speaker. - Almerimar, Spain
Theme That Anchorage
Every anchorage has its own special theme. Some offer ants. Others prefer mosquitoes. Anchor further out and you’ll reduce the pests, but then you get longer scope, bigger swells, and more creative ways to get soaked returning with groceries.
When we arrived in New Zealand after ten days of hard sailing from Fiji, we were greeted not with a glass of wine or a friendly customs officer, but with a full-scale ambush by no-see-ums. These little buggers are smaller than a grain of sand, sneak through bug screens, and bite like hell.
Every anchorage has its own special 'vermin theme' but anchoring further out will reduce the pests.
One of our friends got bitten and ended up with a leg infection so bad she couldn’t walk. So after ten days of seasickness and night watches, she spent two more weeks locked in her boat in agony. By week two, cabin fever had descended into depression. And frankly, the rest of her family wasn’t far behind.
In Suriname, vegetation dislodged from further up river kept jamming under our pontoon, offering free conveyor belt rides to exotic ants, spiders and snakes from deep in the Amazon jungle. We thought we’d be safer anchored mid river, but no. We were hit by a huge tree truck and even watched an anaconda slither across the water and up a tree faster than a cat on a hot tin roof. We quickly realised an anchor chain would prove no less of a challenge. A buddy boat of ours in the San Blas islands unzipped their stack pack one morning to find one curled up in the folds of their main sail.
We realised an anchor chain would be no problem for a tree climbing and semiaquatic anaconda. Suriname River, Suriname.
I once found a bat inside my tea mug. Yes, a bat.
Despite scrubbing and soaking our market veg, in Asia before bringing onboard, cockroaches still found their way in by hiding in the folds of the shopping bags. We didn’t fully get rid of them until we reached the Med.
In some places, the food packaging is half the problem. Especially corrugated cardboard. We’ve found cockroaches in flour, pasta, cereal boxes, and even inside the folds of a UHT milk carton.
In Asia, cockroaches found their way from the market by hiding in the folds of the shopping bags. Raja Ampat, Indonesia.
Top tip: Don’t just wash your fruit and veg. Wash the bag too. Ideally, soak all fresh produce in a sterilising solution like Milton, then rinse it off before it crosses the companionway. Not perfect, but it helps.
Silicone your cupboard gaps. Seal every food item in a plastic container. Discard the cardboard. If cockroaches still invade, try sugar, boric acid, and flour rolled into little bait balls. And if that doesn’t work, it’s time for a full roach bomb. Just make sure you evacuate the boat, remove all food, and preferably don’t come back until the smell fades and the corpses stop twitching.
Weevils, Protein, and Denial
Arguably, worse than cockroaches are weevils. Tiny black bugs that love rice, pasta, flour. Basically everything in your pantry. Even sealed supermarket bags are no barrier.
Weevils - tiny black bugs - love rice, pasta, flour. Basically everything in your pantry, so seal every food item in a plastic container.
Once they’re in, they’re a nightmare to eliminate. In many parts of the world, weevils are so grimly prevalent that cruisers often just cook and eat the food with the weevils still in. I haven’t met a long-term cruiser yet who, after discovering weevils in their last kilo of flour, hasn’t baked the loaf anyway and simply accepted the extra protein as a bonus. And in truth, it won’t hurt you. It’s just something you won’t read about in travel brochures.
Another top tip: Freeze or sun-bake dry goods after provisioning. Kills the larvae.
Some cruisers hang their produce nets under the solar arch to keep them in the breeze which minimises the fruit flies and wasps. You can also make traps with old plastic bottles. Cut off the top half and invert it into the bottom half. Add sugary water or beer, and hang them fore and aft away from the cockpit and companionway.
Make traps with old plastic bottles. Add sugary water or beer and hang them up away from the cockpit and companionway. Vounaki, Greece.
The first line of defence is a bug screen. Make sure you have bug screens for the cockpit as well as the hatches and windows. Even the tiniest gap is enough to let in a determined stowaway, so ideally go for Velcro or elasticated seams.
Important note. Never use mosquito coils anywhere near a net. We have many horror stories about that little inflammatory combo.
The first line of defence is a bug screen covering the cockpit, hatches and windows. S’V Mothership
Ant Lion Metamorphosis
Sometimes though, the whole itchy nightmare turns into something wonderfully allegorical.
What started as a flying ant invasion became Entoclash, Darry’s YouTube channel where bugs get origin stories and personalities.
While the rest of the family cursed and swatted our way around the world, he transformed it into a passion… and monetised it.
An ant invasion transformed into Darry’s YouTube channel Entoclash, a passion he continues to this day. https://www.youtube.com/@EntoClash
He even kept ant lions on the boat. Those weird, ugly, ferocious little sand-dwelling deathtraps that spin themselves into a cocoon of silk and sand, then emerge as elegant, dragonfly-like creatures with wings and just enough time to mate before they die.
Frankly, a better metaphor for this mad life afloat than I could’ve written myself.
Beer Botox and Meat Ants
Returning to the cockpit with the parents, I was mid-rant when I took a swig of beer and a wasp instantly and painfully botoxed my bottom lip from inside the can.
I swatted the bloody thing into the hummus, covering everyone with legume-based dip. With a tasty hint of lemon. Darry gently scooped it out and cradled it in a bottle cap to feed it to his burgeoning Australian meat ant colony below deck.
It was time to call it a night.
If you want more straight-talking tales from life afloat, and information about bugs and pests on sailboats, then you’ll love our upcoming book. We're inviting early readers to join the pre-launch crew and get behind-the-scenes access as we wrestle it into shape. It’s honest, unfiltered, and occasionally useful. Sign up here to get involved, give feedback, and be part of something that’ll either be a bestseller or a brilliant cautionary tale.
