After all I've heard in the last ten days about the situation at your house, this really doesn't surprise me at all. Two days ago, we heard of how insane Chad is and you need to find another place to live. Today, Chad is ok and Mr. Biggles is being put down because he attacked someone. The poor little guy is probably reacting from environmental conditions. I would probably attack too if I were in his position.

As someone said, have you taken him to the vet to be 100% sure there is nothing wrong with him? This would seem necessary to eliminate all possible causes.

These stories make me so sad I can barely type this. It seems like the little guy never had much of a chance. I'm sorry Mr. Biggles.

I have to say: please consider pet ownership more carefully before adopting again. Make sure you know all there is to know about the pet you're bringing home with you. Consider the pet's characteristics as well as the people' characteristics that the pet will be living with.