Question
QUESTION: Hello,

First, I apologize for reaching out to you; I抦 desperate and did not know who to turn to because I needed an objective, scientific, unbiased answer rather than one connected to selling a product.

A few weeks ago, I heard a small bird in our walls and by the time I tried to locate the precise spot it was in, the sounds stopped. A few weeks went by before we soon noticed many little gnats flying around the house. At first, I thought they were fruit flies but could not find any rotted foods and/or visible rodents around. Several days ago, our house has been overtaken by MANY large, blackish, flies swarming around. I抦 convinced there is something dead in our walls (most likely the bird) and the new occurrence of the insects are the result of blow flies hatching. I have used many strips of sticky fly tape around the house and they are catching many each day.

That said, what should I do?? Are there any concerns with disease considering there are so many? Should I call an exterminator? My issue with that is we have an 8 month old and I抦 concerned with having chemicals laced throughout the house. Should I try to rip out drywall? What a pain that would be匢 just don抰 want the flies to reproduce by the thousands like the horror stories I抳e heard匢抦 sorry for the questions, but I抦 worried. If they eventually die off, then I抣l suck it up but if they will continuously reproduce, I don抰 want our son to have to deal with that either; especially with the possibility of diseases. Thanks so much!!

Best,
Tony from Baltimore

ANSWER: Tony,

No apology necessary that's why we are here. First, the small gnat-like flies are unrelated to the large flies. Young flies are maggots (worm-like) NOT a smaller version of the adult flies. The large fly could be a blow fly in which case they may be developing on the dead bird. In this case the flies will go away once the carcass has decomposed (days - weeks). The flies will not continue to breed in the walls unless there is a continual source of dead animals.

I would not expect an average size bird carcass to support the number of flies that you describe. So, if the flies continue for more than a week you might want to catch a few and have them identified by the Cooperative Extension office near you. Here's a link http://baltimorecounty.umd.edu/ and the id should be free or low cost. If they turn out to be something other than blow flies post a follow up question.

Jack DeAngelis
http://www.livingwithbugs.com



---------- FOLLOW-UP ----------

QUESTION: Thank you so much for the quick response. Just a few follow-up questions: are the gnat-like flies something to be of concern? Where do they come from? Lastly, considering the carcass will decompose (I figure won't be too long for a smaller bird), would you worry about getting an exterminator in and/or ripping out the drywall to find it? Sorry again for all the questions...Thanks so much!

Answer
Tony,

There are lots of small flies so it is hard to say what they were. There's no reason to be concerned. If they occur again try to capture a few for identification. It is not necessary to treat the larger flies in any way. As I said, if they don't go away soon then collect a few and get them identified as well. The Extension office will be able to help with both.

Jack DeAngelis