I have a 6 month old Boston, and lately he has been showing what i think might be aggressive behavior. Sometimes when he is laying on the couch with me he will roll onto his back and start wiggling around, make a low growl/whine, and nibbling on anything around him, including me! It isn't a full blown hard bite, just nibbling, but when he does this I usually take him off the couch and put him on the floor. He will then start barking louder and get an aggressive stance and his eyes will get extremely dilated. What should i do about this? Has anyone else encountered this behavior? Thanks.