I hate roost mites. Roost mites (or chicken mites, or red mites) are nearly invisible blood-suckers that are transmitted to chickens by wild birds. They multiply like crazy in warm weather. They bother the chickens and can even kill them under the right circumstances. And I hate that creepy-crawly feeling! Ewww! Get ’em off me! Humans are a non-target species, but still … yuck!
I have an article about them here. Roost mites live in cracks and crevices in the chicken house, in littler, and especially on roosts and in nest boxes. Roost mites are easy to control once you know they’re there, but they’re pretty stealthy — right up to the point where their population explodes and they’re everywhere. Roost mites are particularly dangerous to broody hens, who sit around in the danger zone 24/7, instead of spending all day outdoors like the rest of the hens.
While roost mites are easily killed with insecticide, this doesn’t kill the eggs, so it usually takes at least two applications to get ’em. More, if you miss any. I don’t know about you, but spending my summers spraying houses over and over with bug poison is not why I got into alternative agriculture. It’s unaesthetic.
Still, you gotta take care of the hens. When using insecticide, I prefer Malathion, which has almost no persistence at all (its half-life is only eight hours), so pesticide build-up is a non-issue. It’s also nearly impossible to poison a chicken or yourself with Malathion. Some of the things recommended in old-time poultry books were amazingly toxic (nicotine sulfate, sodium fluoride), or poisonous, carcinogenic, and generally disgusting (creosote). Don’t use those.
For longer-lasting protection, the traditional solution is a good one: oil the roosts with any kind of non-drying oil, and it will kill the mites. The oil will stay liquid and potent, at least in the cracks and crevices where the mites prefer to hide. Many oils have been used for this. Linseed oil works and smells great. Used motor oil also works great and is free, but it’s less pleasant than other oils. I changed the oil in my tractor yesterday and used the old oil to paint roosts areas around nest boxes that looked like it could use it. The dry wood soaked up the oil very quickly, so it’s not like the chickens are going to leave oily footprints everywhere. If I’d had a bucket of used french-fry oil, I would have used that, though I’m a little concerned that edible oils might attract mold or insects or french-fry pixies or something. I’ll try it someday.
The last time I did this, the treated areas seemed to stay mite-free for over a year, in spite of the wood seeming completely dry to me. Mites are almost microscopic, so no doubt they experience things differently.
As always, it turned out that anything that causes me to spend time in the chicken house resulted in my noticing things I’d missed before. (Half of farming consists of slowing down and paying attention.) I found mite-filled areas in places under the nest boxes where I had never suspected them before, though I’ve had that nest house for years.
The last time I did this, the oil smelled to high heaven. Something must have been wrong with the engine that the oil came out of, or the oil must have been a million years old. (Well, okay, all oil is a million years old. That’s why they call it a fossil fuel. But you know what I mean.) This time, it didn’t smell at all. Painting roosts is an odd way to monitor engine health, but there you go.
The other things I need to do are to reattach the door to the nest house so I can exclude the hens at night and keep the broodies out of there (It blew off in a windstorm and I haven’t gotten around to reattaching it, since I usually leave it wide open anyway) and move all the houses to a new patch of ground, which will leave most of the surviving mites behind. Finally, I’ll take my remaining wood-stove ashes and dump them in the hens’ favorite dust-bathing sites. Juicing up the dust baths with ashes helps rid the hens of lice and mites.