The relationship between people and companion animals, on the one hand, explains the bites and zoonotic diseases that occur among those with companion animals and, on the other hand, appears to enhance the psychological and physiological well-being of many people. Presently, no less than 56% of households in the United States have animals, typical of developed countries around the world. It is well documented that people denied human contact do not thrive well. All indications are that companion animals play the role of a family member, often a member with the most desired attributes. Animals play special roles for children, aiding the teaching of nurturing behavior and appreciation of nonverbal communication. Ordinary interactions with animals can reduce blood pressure and alter survival after a heart attack. For some, pets increase the opportunities to meet people, while for others pets permit them to be alone without being lonely.