I have a two year old dog who came from an animal shelter, and is a corgi/chihuahua/mix. He has always been a strange and playful dog, and always enjoyed doing his own weird tricks. However, just recently, I and everyone in my family, have taken interest in something I’ve learnt to be fly-biting. He has done it since he was a puppy, along with other compulsive behaviors like chewing on his nails and obsessively licking himself. I told my vet about him chewing on his nails, and he said it was not an issue. He just had a checkup a few months ago, and he was cleared as a perfectly healthy dog. I can’t quite figure out what fly-biting syndrome is, and how worried I should be about it. He isn’t aggressive when it happens, and just seems like a slightly more paranoid version of himself. He actually does go crazy when there are actual flies around him, and even loses it if I play a fly sound off of YouTube. I’ve always just thought it was his anxiety, but now I’m worried. What should I do?