I am seeing little black floating things and i am nearsighted. what are they?

For how long?: Depending on how long you have had floaters and how irritated you are by them will lead you to go see an opthalmologist. Possible er causes: retinal detachment, or retinal loss, or bleeding within the eyes. But those would be an emergency and i don't think you would have time to ask online. Unless you had them but never saw a dr. For comfort, slightly darker eyeglass lenses may help.