Our dog was acting completely, 100% normal when we came home from work. Excited to see us, playing with his toys, eating his dinner. Totally, perfectly normal. While we were cooking dinner, he noticed a fly. He chased it around for a minute, and then it landed on him. Literally at that moment his behavior did a total 180. He got unsettled, scared, running into his crate. We couldn't get him out for over an hour. At first, I just thought he was scared and was being a goof. But he has been acting this way now for several hours. He is hiding in corners, and won't eat or drink, and panting heavily, and was even acting unsettled during our walk (but he did still have his normal nightly poo.. not sure if that matters). This literally came out of left field and I am so confused and worried. Any advice or anything would be appreciated. If the behavior persists another day, we will definitely be taking him to the vet.