Tortoises use a combination of vocal, visual clues, and smells to communicate with other tortoises. They may also communicate through touch, either by exploring with their mouths, bumping into something, or stepping on it to feel under their feet. ( Tortoise Behavior / By Matthew & Kateryna )
My daughter was able to have the Timmy the tortoise chase her around in circles from the kitchen and living room (three or four times). It may be the shampoo scent in her hair. She was at close eye level with the tort and started to back away while the tort continuously followed her at a high rate of speed. Both our torts occasionally do a dance on the carpets by swinging their back shells from side to side which is a form of communication interaction to us and the other tort.