In all likelihood they are Black Soldier Fly Larvae (BSFL) for short.
They're not habitually in indoor bins but can be common if your bin is outside. Alternatively they could possibly come in from a manure pile that was outside that you fed to your worm herd.

They'll eat a huge amount of food, and not wait for it to decompose. They can live side-by-side with your worms. But they are a fly larvae and will morph into a fly.

Do they look like these?

http://images.google.com/images?q=black+soldier+fly+larvae&sourceid=ie7&rls=com.microsoft:en-US&oe=utf8&rlz=1I7GGLG_en&um=1&ie=UTF-8&ei=BAPySqLNGILssgOEy_EK&sa=X&oi=image_result_group&ct=title&resnum=1&ved=0CBAQsAQwAA

Pick them and feed them to the birds or koi

Yes, that is what they look like. My bin is outside under
my garage. They do eat a lot of food and I think they stink. How can I adjust my bin to not attract them and
to get rid of them.

You may not want to get rid of them. The link below has lots of info.

Here is a link that might be useful: http://blacksoldierflyblog.com/

You're right. After reading that they don't eat the worm
eggs or bother the worms, I'm ok with them. I see where
they are high in protien and fat. My chickens will love them.
Thank you for your help.

You may even consider starting a separate bin for the maggots. Although they won't harm the worms directly, they can produce enough heat to make things uncomfortable for the worms. The link below shows my basic BSFL bin. You would not need much bedding in the larger bin - just enough to make the mature grubs "comfortable" until you take them out to meet your chickens.

Here is a link that might be useful: DIY BSFL bin

I always get a chuckle when I read posts of people just discovering BSF. Mostly because I am insanely jealous of places that get them naturally. They do not occur here in AB, Canada but I wish they did. By what I have read about the amount of waste material they can consume, the fact they self harvest themselves out of the compost and the fact they are a good protein and calcium feed source makes me think about moving to warmer climes. That plus winter gets depressing some days.

If you have family and a job where you are at, I wouldn't move for maggots!
LOL

BSF is a great boon to your composting. You should definitely encourage/ manage them as they are potentialy more productive composters than worms.

Here is a link that might be useful: Black Soldier Fly

I think I am having more success raising BSF than I am worms.
I want the opposite.

Hey rom.calgary.ab I'm in the same situation (and province). I'm thinking of picking up a few from a pet store to see if they'll breed indoors. They're sold as "Phoenix worms" for feeding to reptiles.

plumiebear, I enjoyed your link to your BSF bin. I have a few questions. How does the grubs get from the food bin up
and over to the the big bin? Do you put a top on both bins or just the big bin? With a lid on the large bin, how do the flys get to the food to lay eggs?
Thanks again for your link.

boreal_wormer, I've found them for sale as well. From what I've read so far you will be able to mature the BSFL into the adult fly but as far as getting them to breed in controlled environment it will take some work (and money). I think to be able to get them to reproduce in our climate you'd need a heated greenhouse (or quonset?) to be able to provide bushes, grass, (some kind of natural environment) for them. In the house is out of the question for me, had to do a bit of convincing to have the worm bins indoors. If you have some success with this be sure to post. I'd definately be interested.

loftin60, the mature grubs (darker color) are able to crawl up the vertical surface of the smaller food bin because there is always condensation on the walls. There is a lid only on the larger bin.

I thought that soldier flies were no longer laying eggs this late in the year, so I did not drill any access/exit holes in the bins. However, a few days ago a fly actually "hatched" from one of the pupae in the pupating (larger) bin. I decided to transfer the grubs to larger bins. This time I drilled 3/4" holes and moved the setup outdoors in case the newly emerged fly is able to find a mate and returns to lay eggs. I doubt it, but you never know.

Here's a video of what my small colony looks like during the transfer.

Here is a link that might be useful: BSFL colony

That is a great video! Is this a dedicated BSFL bin or is it shared with your worms? How did you get the grubs? Did you buy them or was lucky they came to you? How can you attract them to your bin? They don't seem to be as sensitive to light as the worms are. That is a very interesting concept!

Sandra

Rom.calgary,
I'm in Ont, and picked a bunch of worms out of a horse manure pile last week. I was putting them into their new home, in a bin in my spare bedroom.
Damned near freaked when I saw a BSFL in amongst the worms. He obviously was abiding in the manure pile.

Can you find some manure piles to root around in (get some worms and hopefully some BSFL?)

Thanks, Sandra. It is a dedicated BSFL bin system (small bin inside a larger bin). I'm in No. California and by the time I learned of BSFL it was too late to try and establish a local colony to maintain over the winter. I ordered a "BSF multi-stage starter kit" from Jerry at blacksoldierflyblog.com. What you saw in the video is what the starter kit developed into after 3 1/2 weeks. Since BSF have nearly stopped egg laying in Jerry's area, he's stopped selling the starter kit until next spring. You could contact him about buying just grubs without the eggs.

Like jasdip described, people often find them in their compost bins, manure, etc. If the conditions are right they can quickly dominate a worm bin. (steamyb had a bad experience with that) When that happens the bin becomes too hot (85-100ºF) for the worms. You can probably attract BSFL next spring. I suggest starting a dedicated BSFL bin rather than trying to incorporate them into a worm bin. See #2 on this FAQ:

Here is a link that might be useful: BSFL FAQ

jasdip, haven't heard of them naturally occuring in AB. My family has an acreage a couple hours out of town right in the heart of horse, cattle and farming country and I haven't noticed any.

The "neighbor" keeps beef cattle on his quarter and we keep a compost pile as well and have only noticed worms and the more common flies around here. I haven't actually rooted around a manure pile though. I've tagged along with him to move cattle, just to see how it's done, but I'm not sure what he'd think of city boys that want to dig through his manure for bugs.

BSF wow always wondered what those uber productive things were. I compost in a huge open bin, kitchen scraps go into tidy cat buckets with the bottom cut off and then buried to its hinged lid works great for my maggots. when full I pull the bucket and move it.

minitrucker, that's a great idea! Simple and sounds like it would work to provide the hot & wet environment the BSFL prefer while temporarily quarantining the food waste. Once the grubs have processed the material, it will be perfect for the other critters to finish it off. Any mature grubs could migrate to the "normal" part of the bin to pupate. I may try this if I can't get a dedicated BSFL bin to work next Spring.

I had these bugs in my compost bins and I keep killing all the pupas. Now I guess I shouldn't have kill them. Oh, well you live, learn, and die.