My Kitten's strange behaviour

[Lizzyliz78]

I have a 9 week old male kitten. He's a great cat ..... most of the time. Recently I've noticed something very strange with his behaviour. I've had cats all my life since I was a little girl, so I'm pretty much intune with what to expect out of them. I will also mention I have a 3 year old male as well. Cleo (the kitten) loves to play with his toy mice or any kid of paper ball. At times he will play alone which is fine but within the last couple weeks he has been hissing while playing alone....I've NEVER witnessed this with any kitten I've owned. Along with the hissing, it looks like he's panting but, there isnt any reason for him to do it....when he starts "panting" he goes crazy....I call him the "Devil Cat" when this starts cause he will jump really high into the air about 5 times in a row then bolt to another room, jump around again and bolt to another room....this is when the hissing starts. At first I thought he was panting cause he was tired from running crazy or he was hot, but the panting will start before the "Devil Cat" episodes. As soon as the panting starts I know he will start going crazy any second after. Does anyone else know what is going on with him....??? Or have you seen this with other kittens.....??? Another "issue" I wanted to ask about was why the kitten walks behind my 3 year old cat and bite his legs as he walks or if he's sitting on the bed etc....I've tried getting the kitten to stop biting my older cats legs but nothing works, even the cat turning around and biting the kitten hasnt stopped him either.....I honestly thought the kitten would have learned what he can do and what he cant do when it comes to the other cat, but he hasnt. What can I do......???