Dogs

You may be shocked by what's living in your home — the bacteria, the fungi, viruses, parasites and insects. Probably many more organisms than you imagined.

"Every surface; every bit of air; every bit of water in your home is alive," says Rob Dunn, a professor of applied ecology at North Carolina State University in Raleigh. "The average house has thousands of species."

Dogs can sniff out people, drugs, bombs, cancer and much more. In her book Being A Dog, Alexandra Horowitz explores the mysteries and mechanics of canine noses. Originally broadcast Oct. 4, 2016.

Animal behaviorist John Bradshaw's books Cat Sense and Dog Sense detail what cat and dog owners should expect from their animals. Cat Sense originally aired Sept. 5, 2013. Dog Sense originally aired May 26, 2011.

Kittens don't play -- they hunt. And their aloof appearance has evolutionary roots. A new book explains cats' mysterious nature and how their relationship with humans has changed over the years.

Naturalist Mark Derr says our friendship with dogs and wolves goes back thousands of years more than previously believed. His new book explores how the relationship between humans and wolves developed.

Many of Spencer's novels feature a turning point -- a dreadful, unplanned act committed by one of the characters. In his latest book, Man in the Woods, a carpenter accidentally kills a man, which leads him to question himself and his relationship with God.

Former Saturday Night Live writer and producer Robert Smigel uses animal puppets to say and do the lewdest things. His most infamous creation is Triumph, The Insult Comic Dog, who made a name for himself "pooping" on guests of Late Night With Conan O'Brian.

In his book One Nation Under Dog, Michael Schaffer investigates the booming pet-care industry. He discusses how the $43 billion business reflects our ideas about consumerism, family, politics and domesticity.