My pinky and ring fingers get pins and needles sometimes. what could be the cause of this?

Ulnar nerve: The ulnar nerve supplies feeling to part of your ring finger and the pinky. It travels from your neck, across your elbow and then into the palm of your hand. A common area where it can get irritated is at the elbow. Avoid leaning on your elbows or bending them excessively to minimize irritation there.

Compression of ulnar: Nerve at wrist or elbow, large breasts, brachioplexus injury or neck spine disease or even very localized brain injuryt.