My male is a side/butt eater and I was feeding him smaller rats because if he couldn't get it down he would leave and ignore it. I can get him to strike it again (you know after he mangled it the first time lol) but he'd normally just give up again. It wasn't until recently that I've been able to get him to eat more appropriate sized meals. After the rat has completely thawed I run the rats head under warm water until the head is warmer than the rest of the rats body. Since generally speaking the head is supposed to be the warmest part of the body I figure this is like marking the spot of where he needs to swallow first. So far so good. He's managed to eat the rats head first ever since.