Rapid Tapping/Shaking Of the Claws! HELP!!!

by Shelby

Okay, I have a Red-Eared Slider turtle who is about 2 years old. Tonight I was putting my finger up against his aquarium, and he came up to it. After a few moments of just looking, he brought his claws near his face (up to my finger) and began making a rapid, repetitive tapping or shaking of his claws. I have never seen him do this, and I'm a little worried. Can someone please help me? It is much appreciated! Wolverine (my turtle, named after his claws!) thanks you as well!