I am really worried about my cat Taz. He is almost 16 months old, and has never had a litter box issue before. 3 nights ago, he crept up to the litter box and was peaking inside and jumped up in the air and ran away. I checked the litter box, and there was nothing new there. It is in my room under my desk where no one but me ever goes, so I know that no one has ever scared him while he was inside. He still uses the litter box we have in the basement, but that door is normally closed (our other cat lives down there and hates having him around). I know it's not a UTI or anything, since he is still able to go to the bathroom, just wants nothing to do with his box. Every time i try to bring him near it, he puffs up and runs away from it. I've never seen this happen before, has anyone ever dealt with this before? I'm scared that there's something wrong with him..