Just thought I would share.
He loves to chase his brother on foot while his brother rides his bike/scooter/rollerblades, he loves to chase the little jeep 4*4 riding car thing we got. He'll ride it in, but he would much rather be chasing someone else while they drive it. He will chase the little quad 4 wheeler their grandpa bought for them and anyone coming down the drive if he is outside as such an opportune moment.
If we aren't careful he will chase his grandparents riding lawn mower.
He chases and laughs like a maniac, it must be exhilarating for him somehow.
[edit]Thought I might mention that he is 9.[/edit]