Housefly larvae are about the size of a grain of rice, and are white. Soldier fly larvae are dirty-white to grey, about half an inch long and roughly the same circumference as a number two pencil. Based on your description, I'd lay odds that you have soldier fly larvae in your bin.

If I understand you correctly, you had the bin outside, but recently moved it indoors due to heat. Is that right? Know that, while adult soldier flies will not willingly come indoors and there are few suitable places indoors for the larvae to pupate, it is possible that they may crawl from the bin, find a nice pupation site, and develope into adults that will be trapped inside your home. A bin with a resident population of soldier fly larvae is best kept outdoors.

Know, too, that soldier fly larvae are drawn to all environments of decaying organic materials, not just to food scraps or stinky, anaerobic systems, as is the case with houseflies. It is normal to find them in healthy worm bins and compost piles. Their presence in your system is not indicative of something you did wrong, rather, it is a normal and, while admittedly kind of icky, highly beneficial.

Consider putting the bin back outdoors in a location protected from sunlight but through which air can freely move. Keep the bin damp (the soldier fly larvae will help with this as their activity tends to increase moisture in worm bins) and the worms will easily tolerate the high temps.

Kelly S

The bin was in the garage, then the den, then the bathroom. this bin has never been fully outdoors. It is possible that a soldier fly got to it while in the garage on a day the door was open.

So keeping it damp will help them tolerate 90-100+ degrees?
Worms have an optimal temperature, but how much can they tollerate without keeling over? both cold and hot?

hi ana, the worms can survive those temps outdoors as long as the bin is kept moist and in a cool spot. I have temps which average between 90-105 ish for about 6 months over summer but it's important to find a nice cool location like under a shady tree where the bin wont get any sun on it, and you cant let it dry it, if you keep it moist in there the worms will be fine :)

dang :) I made a couple of errors in my post:

" you cant let it dry it"

that should have read "you cant let it dry out"

and " I have temps which average between 90-105 ish"

should have read "I have temps which average between 90-109 ish"

trance

Ana, I have worms (5 bins in my little green house here in dallas and temps are regularly 100 and they do fine, they are under the planting bench so they are shaded, I do get a lot of soldier fly maggots but don't see many actual flies just once in a while and they sure keep the cantaloupe and strawberry trimmings under control just sprinkle some compost on top of the feedstock(yucky spaghetti, and rotting cantaloupe) and you'll never see 'em.

Ana53..I have indoor bins that have never been outdoors with masses of BSF's show up suddenly. I believe the eggs are on the food scraps I put in. If there is more food than the worms can handle, or perhaps the bin gets too warm and the worms go down to lower, cooler places in the bin, then the BSF eggs have time to hatch and step up to eat the OM. Fruit flies were a problem back when I first started my bins. Now that my worm population is large, the fruit fly eggs do not have time to hatch and they are no longer a problem with any amount of fruit I put in. (This information comes from my observations, so it is IMHO)