Annoying bugs are surprisingly low this year, even before I put the trap up, I'm not complaining. Yes I have caught deerflies, mostly what we are catching right now is moths. I empty it most days by putting the bin in the coop and taking the lid off. Many of them are still alive...the chickens go crazy when they see me coming.
Horseflies and deerflies like to go for the highest part of you. For the morning runs we cover our hats with double sided carpet tape ( Stihl hat is best ). We come back with 100s of the &^%$ on the tape. YMMV