Why Do Dogs Have Tails?
Why do dogs have whiskers? Why are dogs' eyesight black and white? Why do dogs have so many babies? Why do dogs have tails and we don't? Why are dogs thumbs so high on their paw? Why don't dogs sweat? Why do dogs roll in the grass? Why aren't dogs and cats friends? Veterinarian and dog scientist Jessica Hekman has answers.
"Why do dogs have whiskers?" - Hazel, 7, Duxbury, VT
This episode features coloring pages by Aaron Shrewsbury. You can download and print Sleeping Mama Dog here. There is also a quiz coloring page! Download and print Dog Breeds and see how many you can identify, then check your answers here.
"Dogs don't actually rely on eyesight as much as we do. Their noses are really, really good, and so they have these other extra good senses that help them out more than ours. Just as their noses are better than ours and they use them to explore the world more, they also have whiskers to help them feel their way around in low light.
"So if you were walking around and you couldn't see very well and you were coming close to bumping up against a wall your whiskers would warn you before you bumped up against the wall. That's why dogs and cats have whiskers. That's just another way, another sensory input system that they use that we don't really need partly because our eyes are so much better, but also partly because we aren't as interested in moving around in the twilight as they are because they're predators and that's a really good time for them to hunt."
"Why are dogs' eyesight black and white?" - Lola, 7, Oakland, CA
"Actually dogs can see some colors, they don't actually just see black and white. They see fewer colors than we do. They don't actually see red, but they can see blue and green and yellow.
"Then the question I think is really why humans can see red, right? And the answer is probably that our ancestors evolved that ability so that they could see brightly colored fruit like red or orange fruit, which was probably an important part of our diet millions of years ago. If you look at other animals who can see reds, other primates who are very interested in fruit and also birds who are very interested in fruit can also see red. And again just like with the whiskers question, dogs don't rely on vision as much as we do so that could be another part of the story, that having detailed color vision is just not as important for them."
Clarification: In the audio for this episode, Dr. Hekman misspoke about how horses walk. They walk on one toe.