- Hollow hairs help them stay warm in the winter.
Have you ever seen a deer that has snow on its back that doesn't melt? It makes people shiver to think about walking around covered in snow --- isn't the deer freezing? However, it's actually that frozen snow that shows just how warm a deer is. Deer and moose have hollow guard hairs over their furry undercoat that helps keep all of their body heat inside. They are so insulated that their body heat doesn't even escape enough to melt the snow on their backs. They don't even feel the cold from the snow.
- Deer are created to eat vegetation.
White-tail deer have been documented to eat hundreds of different kinds of vegetation, and they have two qualities that help them get the most from their food.
First, white-tailed deer have 32 teeth, but they don't have any upper teeth in the front. Instead, they have a hard palate with a rough texture that helps them grind food, like molars for humans.
Second, deer also have a four-chambered stomach. The food travels from the mouth to the rumen, which has healthy bacteria to begin digestion. Then the reticulum circulates the food back to the mouth to chew again. The omasum then pumps the partially-digested food into the final chamber, called the abomasum, which is like a human's stomach. It finishes the digestive process.
- You can tell a deer's age by its teeth.
Deer have baby teeth, just like people do, and lose them at about 18 months old. Their adult teeth then grind down year after year while foraging, and they lose about 1 millimeter of height each year. Scientists can tell how old a deer is by how much their molars have been ground down. (Read about white-tailed deer rut.)
- Deer are good swimmers.
Most people know that deer are fast on land. They are able to run up to 40 miles per hour and jump 6-8 feet high. However, they can also swim up to 15 miles per hour. That's really fast considering they don't have fins, flippers or webbed feet!
- Their white tails have more than one signal.
Deer flash their tails when signaling danger. However, their tails also signal danger in other ways. When the tail is down and the hairs are flared apart, it is signaling nearby alarm. When it pushes its tail down tightly against its rump so that you can barely see the white, it is signaling danger that is close at hand. The upright white flag is used to help deer stay together when they are running from harm.
A tail that is swishing back and forth gives the all-clear signal when a deer is relaxed.