Common behaviours that come with sexual maturity are circling feet while making a humming sound, spraying, being territorial about your hand in his cage, biting (hard) , lunging, and grunting. My bun Thumper went through all of this. He started out as a sweet little boy and turned into the devil. Now it's a month after he's been neutered and he's a sweetheart all over again. Though remember that neutering may not solve everything. It depends on the rabbit but it should calm those hormones down. Although never back down to a biting bun otherwise it won't be hormonal behaviour it'll be learned after awhile. What you do is put his his head on the ground and hold it for 2-3 seconds while firmly saying no. It usually works because this is what the mother bunnies do! If that fails then a cage timeout for about 5-10 minutes will do. But you'll have to not use his regular cage because you don't want him to connect his little cozy den with bad behaviour so find an alternate cage. It doesn't need to be huge but enough space that he can hop 4 times. But if your rabbit displays any of those behaviours listed then he's in for a neutering, but make sure his testicles have dropped before making any plans
