"There are midges out."
Translation:Tha a' mheanbh-chuileag ann.
Meanbh-chuileag means, literally, "a small fly" and I suspect that is why the article (an) is needed so that it is clear that we are talking about "the small fly" (i.e. the midge) as a collective noun rather than about "a small fly" .... if only they did only come in ones and twos! :-)