My cat, Bamf, is a nervous wreck at times. He was my daughter's cat, and she gave him to me when they moved into a home that doesn't allow pets. For the first year we had him, he stayed in one room of the house, coming out only to eat and use the litter box. Bamf would crawl underneath the comforter, in order to feel more secure. The only way we knew he was there by the big lump in the middle of the bed. He wasn't always like this. He seemed to gradually become anxiety ridden, first being scared of flip-flops, then hating to be alone. We realized this when we would come home and find the lump in the middle of the bed. He is also scared of thunder, heading for the dark corner beneath my desk on the rare occasions it storms. We have given Bamf a secure home, but we accidentally sit on him when he hides under the throw on the couch, or when he hides under the comforter on the edge of the bed instead of in the middle. He's affectionate, craves attention, and is a wonderful companion.
