Scared the tar out of Calla. It sounds like a tick. The tick will swell as it penetrates, feeding on bodily fluids. It is easy to get rid of the tick. Carefully smother the tick with petroleum jelly, keeping the jelly away from the snake's eye. This stops the tick from breathing, the tick will just drop off of the snake.
It is pretty rare to see ticks on a captive bred snake. Could this snake have been a recent import?
You should have a parasite panel done by a vet. Ticks spread microscopic blood parasites.
