Photo via YouTube

Scientists are constantly probing for answers to the questions that have vexed humankind. Take dogs, for instance. Why are they always sniffing each other's butts?

Dogs who engage in this canine tradition are not just being rude, they're communicating in a surprisingly complex way. It's just one of many forms of chemical communications that go on everyday among animals.

Reactions, a video series affiliated with the American Chemical Society, explains:

Share your Comments