One day Chewie ran off into the house and didn't come back for a while. Hubby and I finally found him behind a coffee table. He looked up at me with a huge chunk of poop hanging from his mouth

My jaw dropped. Since then we've caught him a couple more times. He'll run off to hide, poop and snack. Why is he doing this all of the sudden? Chewie is coming up on 4mo old. Thanks in advance!