S.H.
The brand Nature's Plus "Animal Parade" makes something called "Warm Milk" which is for things like this.
Look it up online and for reviews. Natural food stores have it.
2) does your son get enough activity and run around time during the day? Preferably in the morning.
3) If, doing horse-play at night, and before bed, all this does is key-up a kid. And then they cannot.... wind-down or sleep. My Husband, used to horse-play with my kids before bed. UGH. And all it did was UNDO, their calmness and get them ramped up. Thus even if I wound them down and made things quiet... his horse-playing with them, UNDID all that and then they could not sleep. Then Husband would say "how come they can't sleep?"
DUH.
Also though, not all kids just fall asleep, in 2 seconds after hitting the pillow.