I have a Fire that came out out of the box striking. He even striked when my son ran by 12 ft away. I held him for about 30 minutes twice a day for the 1st few weeks. Now he still huffs sometimes and a little skittish but he hasn't shown any aggression since. I've had him a couple months now. He only passed on his first meal. The ones I find that have more aggression I spend more time with even though I know a lot of people here would say they're best left alone. I haven't had any issues with non feeding or any other problems.