Some research suggests that low levels of serotonin or high levels of dopamine are associated with self-injury behaviors, so there may be a biological basis for the behavior. This is not always true, though. With our son, we discovered that we had accidentally encouraged the behavior by picking him up and holding him to get him to stop. Once we took away any response that he might think of as a "reward", he found his own alternate stress responses. Although the hand-flapping can be a little distracting, it is much better than the head-banging.

For the biting when excited, replace it with clap hands....so when you see him getting excited grab his hands and do hand over hand to clap them...EVERY time and praise for clapping and/or model " I am sooo excited/happy/hyper/frusterated" ect. A token system for when he does not bite, but used another strategy (clapping, stomping, words, ect) is also helpful, just need to make sure the reinforcer is super reinforcing!

I found that suckers or chewy food helped with the biting behavior.

I have even tried applied pressure wrap in in my arms or in a blanket and it just makes him more mad.

I have tried chew rings, toothbrushes, he hates things that vibrate. I try to give him things that he likes but when he is in a tantrum nothing works =0(