My rat is about 9 week old male and seems vey happy and healthy, but just today i was playing with him and picked him up and felt his tummy. He had a hard spot on him rit inbetween the anul and his uper stomach. But whenever I touched it or rubbed it he didnt respond to it,he didn't squeak or anything, all he did was try to get out of my hand so that he can run around and play. I'm a little worried rit now, plz help me find out whats wrong with him, thanx.