Quantum was about 8 weeks old when this was taken (she's now nearly four years old) and her tail stump was still bare. (Short version of the cat story: Owner drives over kitten tail, tail has to be amputated, owner doesn't want kitten sans tail, friend in veterinarian office saves kitten and gives her to us as a housewarming cat). The requirements for cat #2 (Tangle) were "orange, with a tail." He turned up in an abandoned litter in a barn, found by the same veterinarian.
Cat naming note:
Cat #1 is called Quantum. Cat #2 is called Tangle Mint (Tangle for short). Quantum entanglement is what happens when they curl up together. This is why you shouldn't let the physics grad name the animals.