From parasites to insects and large animals, there are many dangers awaiting humans in the outside world. While many think of huge, aggressive animals as being the ones responsible for the most human deaths in one year, this is far from the truth. In fact, the most deadly animal in the world is one that's usually no larger than a penny.

It's easy to forget that smaller insects can also transmit diseases and become a third party in the sickening of a human, which also raises their threat level to the human population. While many of us are thinking of bedbugs when we travel, there are far worse insects out there. Similarly, many species of animals we wouldn't think are normally aggressive, do have the power to end a human life - whether intentional or not. It's a dangerous world out there full of creatures we think are our friends, and full of pesky little buggers that are often underestimated.

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Mosquitos

Mosquitos are responsible for killing roughly 725,000 people a year or more. The cause of this is due to the diseases they transmit, some of which there is no cure for. Some of the diseases they carry include Zika, dengue fever, malaria, West Nile, and those are only the major infections - they do carry more. This is why experts stress wearing insect repellent every year, in addition to setting up citronella candles around yards. Furthermore, screens should be replaced and windows and doors shouldn't be left without them open during the summer months.

Snakes

It's not too surprising to see snakes on the list of the most dangerous creatures in the world, but it is surprising to know they kill up to 100,000 people per year. While they're well-known for being one of the most venomous species in the world, they're also some of the sneakiest. They often reside where people do and the problem arises when anti-venom isn't within reach.

While pythons take prey by squeezing them, cobras spit venom - so either way, it's a lose-lose situation when going one-on-one with a snake.

Freshwater Snails

It's absolutely shocking to know that a freshwater snail is responsible for up to 20,000 lives lost each year, but it's true. Many times, these snails aren't even seen until it's too late.

The reason they're one of the most dangerous is that they release a bacteria called Schistosomiasis, which targets the intestines and urinary tract. This is a common cause of illness in countries where clean freshwater sources aren't attainable.

Assassin Bugs

Assassin bugs are responsible for spreading a disease called Chagas, which takes the lives of up to 12,000 people every year. The bugs themselves don't even look pleasant and are known for parading their fellow insect corpses on their backs after they've drained them dry.

In a human, this bite can cause severe inflammation and infection - and they're found in North and South America, Europe, Asia, and Africa. The next time you think a bug bite isn't dangerous, remember that this bug exists in the world.

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Tsetse Fly

Many people have heard of this troublesome fly as if anyone needed another reason to hate flies even more. They're only found in Africa but are still responsible for killing up to 10,000 people each year. The fly is a nightmare incarnate; it buries itself underneath the skin and can transmit African trypanosomiasis, otherwise known as "sleeping sickness."

To say it's unpleasant would be putting it mildly, as the disease essentially kills humans by wearing them down to the point where they sleep, while the bodies ultimately just shuts down.

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