I have lill bump in back of my tongue. is that std?

NO: Not an std. We all have bumps on the back of our tongues called circumvallate papillae. These help us to taste as well as secrete a type of saliva that helps to wash debris off of the papilla which helps them respond to taste stimulation quicker.

Taste buds: What you are probably seeing are your taste buds. They are on the very back surface and side of the tongue. If you have any concerns, see a dentist.