there is a away to kill them my brother usually puts them in a plastic bag an swings them agisnt a wall usually parlizes them and try to aim not at the nose or this will cause it to bleed (clean as possible ) haha

rats i own them its pretty simple to breed them really
they breed fast as well
put a male in a cage with a female should just do the trick
females go in heat at lease every 7 days ? i think so it's pretty easy to breed them