Plucking his fur

My cat Marty is 10 years old and for the past 2 years his back or tail will twich then he will start to pluck the fur. Latley he hasn't really been doing it as much and his hair is growing back in, but I still catch him sitting on the picking at his back. Could this be because he is alone alot or some compulsive/nerve thing?

It could be a nervous disorder, but I would have him allery tested. Usually when they do this it is because of an inhaled allergy but mostly a food allergy.

Yup, definitely get him to the vet! You have to rule out medical causes first. Then, if it's a behavioral problem, you can try and treat it as one.