In 2016, it was discovered that Americans's top fear is terrorism, but the fact is that terrorists pose a very small threat in the U.S.

The likelihood of someone being killed in an terrorist attack from a refugee is 1 in 46 million and an illegal immigrant is 1 in 138 million, according to the National Safety Council and the National Center for Health Statistics.

Although heart disease, cancer, and motor vehicle accidents are bigger causes of human deaths than animals, you'd be surprised by the dangers they pose annually.

When we say animals we're not talking about your fear of sharks or snakes, we're talking about the more common animals you see on a yearly basis.

1. Bee/Wasp/Hornet

These flying insects are responsible for hundreds of deaths per year in the U.S. Chances are you probably know at least one person who is allergic to bees, so those are the people who are at risk of dying from anaphylactic shock after a sting.

2. Dog

That last thing you want to hear is that these loyal animals have made the deadliest animals in the U.S. list. According to statistics, depending on the year, dogs kill about 20 to 200 people annually which means that you're more likely to die from a dog than a shark attack.

3. Cow

These seemingly calm and complacent creatures are one of the most stealthy animals ever. A report from Centers for Disease Control and Prevention found that cows kill about 20 people a year. The victims were mostly farm workers.

The deadliest mammal in the U.S. is not the animal you would expect to cause the most deaths. Keep reading to find out!

4. Anthropods

Non-venomous insects account for a 85 deaths per year, while venomous spiders account for 70.

5. Pigs

Pigs are also part of the category of animals that kill a few dozen people a year. Again, most of their victims are farm workers.

6. Horse

You'd think rodeo or bull-riding deaths would kill more people than horses, but you're wrong. On average, 20 people die per year in horse-related accidents.

7. Mosquito

Although more than one million people die each year after being bitten by a deadly mosquito, the U.S. doesn't contribute much to that number. Even so, mosquito or tick-related deaths account for hundreds of deaths per year, and it's hard to escape these little buggers in warm weather.

8. Deer  

You've made it all to the end to learn which is one of the most deadly mammals in the U.S., and the answer is probably pretty shocking. How could these serene and beautiful animals be responsible for more than a hundred deaths per year? Well, most of these deaths are the result of deer-vehicle collisions, so it's really not their fault.

Don't be scared to leave your house though, luckily the odds are not in your favor! If you add up all these annual deaths from these animals, it wouldn't reach anywhere close to how many people die per year from heart disease.