Fly, fly, fly away!
Use Raid at the location where the shrimp shells were left, and also at other locations where garbage gets stored even for a short time.
The "nest" is where you see maggots and is likely to be near where you see flies congregate. It can be inside a garbage can. Maggots, if unkilled, turn into flies. The group that departed was probably new hatchlings.
By the way, a dead mouse can become such a "nest". Been there seen that.
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.
Last edited by AllanJ; 10-22-2010 at 09:58 AM.