How can you tell when a ratsnake is hungry?

My adult ratsnake has refused to eat a small rat and a rat pup 3 and 3 times. I have read that they look around their cage for food when they are hungry... is that true? If not, how can I tell?

In my experience, the more common question would be how can you tell when your ratsnake isn't hungry . I guess my only questions would be what is your setup like (temps, size of enclosure, etc etc), and how are you presenting the food?
If everything is optimal, you might need to try an adult mouse (f/t or live) instead of rats.

lol I have only had him a month. He is my first snake. The seller told me he ate a lot that month up to a week before he shipped him. He also told me that it is normal for an adult caver dweller not to eat for a month or so.

I have him in a temporary tank that is a 55 gallon. He has a cork log hide, branches on a stable stand, and a large glass water bowl that I change every other day. I have plain white paper towel on the floor of the tank. Yesterday I raised the temperature in his cage by covering most of the screen top with a towel to keep in the heat that is coming from a 150 watt red bulb. The cool end is around 78 and the warm end is around 82. Before he came to live with me he spent most of his time between 76 and 82 degrees. My Dad suggested the towel to increase the heat and it worked. My snake is still not active though. I am contacting his former caretaker to see if that is normal for him. I had heard he really loved his hide and it looks like he's fallen in love with his new hide as well.

I offered him a live small rat in his enclosure 3 times over the course of 3 days on the second week after I got him and he was completely uninterested. The rat kept trying to snuggle up to him to sleep and my snake was not at all impressed. lol I left the rat in there a couple of hours peaking in now and then to make sure the snake was ok and then took the rat out before I went to bed. I did the same thing the next week with a live rat pup. He has been eating live for the past year so I am wanting to switch him over as soon as I can to f/t. I did not try to feed him last week as the rats really seemed to irritate him. Also I had read that snakes roam around their tanks looking for food when they are hungry. He doesn't look for anything.

Last night I noticed a white bump or skin or something on the left side of the large scale on the top of his head. I also saw him rub the left side of his head along the glass last night as well. I did see him do something like that, but much less pronounced two other times weeks ago, don't remember what sides of his head, though.

I am going to make an appointment for him tomorrow asap so I can have a reptile vet look him over. If he is healthy, awesome. If not, I will need the help. If you have any advice for me please share! I want to provide him with the very best home and care possible.

Darn...I unfortunately have no experience with Asian ratsnakes (on my wish list though lol), only the American varieties. Hopefully someone else will be able to chime in and offer advice. Best of luck!

Thanks anyway!

I took my snake to the vet today and found out why he wasn't eating. I am going to post the whole shebang on my thread "snake rubbing his head" under general herps so that I don't have two threads going about the same thing. Thanks!