New growth on my cats back

Hi, I am new to this but I just wanted some advice, i have noticed this little growth on my elderly cats back this morning, when I first felt it I thought it was a tick but it wasnt. There was a scabby crust that fell off and has left this. Should I be concerned and take her to the vet just in case?

Hello!  This could be one of any number of things, from a small pustule / follicular infection to a papilloma that has been scratched.  It may be sore and there is some chance of it being cancerous, although from what I can see, that was not my most likely suggestion by a long way!   Your vet will have a look for you in context and help to establish whether action needs to be taken.

Ive just found another on her skin but its a a bit smaller than this one

Warts should also be on that list!