My cat has been twitching quite a bit lately. She doesn't seem to be ichy or licking. Its just twitching. Just a little concerned because she never did that before and now it happens all the time when she lays on me. People can't see it but i can feel when she does it. She is 12 yrs old and siamese.
First of all, get your cat to a vet and be sure to do bloodwork. There are very many conditions that can cause that. Siamese cats are predisposed to a lot of conditions, and with a cat over 10 I'd go for bi-annual checkups regardless.
If it's not health-related, it might be overstimulation (for example, when you pet your cat too much at a time and she starts feeling uncomfortable because of it) or pent up energy (then you should play with her more).