Vampires are considerably stronger, tougher, and fitter than humans; able to outperform humans in any physical activity and run at speeds faster than the human eye can follow, a process called "Flitting". Flitting causes a static charge to build up in a vampire's body, which Mr. Crepsley learned to use to force open locks. A vampire's senses are all similar to that of predators, allowing them to see in darkness, hear heartbeats, and track scents. Their bones and teeth are stronger than those of humans, allowing them to endure incredible amounts of physical trauma, are resistant to most chemicals and diseases, and are able to heal and recover much quicker than humans. A vampire's healing factor is not as effective as in most fiction, though they are more resistant to fatal injury compared to humans and other living creatures, and, unlike the beautiful vampires of Anne Rice, most of Shan's vampires are very average, normal and plain in appearance. More abilities include breathing an invisible gas that renders a human unconscious, telepathically communicating with other vampires and humans (three vampires could also mentally command spiders), and locating vampires and humans whose thought patterns they have learned to recognize. The blood of snakes, rats, and cats are poisonous to them.