LOL Before I got a conscience I used to do that with cats and squirrels
This morning doing L2 I got a clear notion of what you can do to the body in terms of reactions like fear, anxiety and other emotions and sensations. You can make certain things pretty real to yourself. Holding an imaginary knife above your hand can get a reaction out of the body. Imagining stand on a high pole with no support and thus almost falling can get fear and anxiety dialed up to the point of actually feeling it as if it is as real as PT.