Reddit mentions of Pet Organics Calm Down for Cats 8 oz.

Here are two things you could do :

1. Get some homeopathic feline calming spray. When I first heard about this stuff I thought it was a bunch of hippie mumbo jumbo. But I bought it as a last resort when I was moving with my cats and they were going batshit crazy. It totally works. http://www.amazon.com/Good-Cat/dp/B000633X1E/ref=sr_1_3?ie=UTF8&qid=1324931791&sr=8-3
   
   
2. Once you have done the whole calming thing, your cat might be less territorial. But if he still seems to be acting nuts you need to discipline him. Don't ignore his biting. Instead spray him with water and yell NO. In the future he'll learn to understand what NO is without any water. Also, if he behaves well for a day, play with him and reward him with treats.
   
   I have adopted three feral cats in the past and these tricks have worked so far. Best of luck! :)