Animals are responsible for over a million human deaths every year, but which ones are the biggest killers?

5. Dogs

dog drinking
Dogs kill lots of humans through the transmission of rabies iStock

Millions of people are bitten by dogs every year, of which it is estimated around 25,000 people die as the result. This is predominantly caused by rabies, with the infection being passed through the saliva. India is worst affected, with around 30 million stray dogs causing 35% of human rabies deaths across the globe.

4. Snakes

Bothrops asper
Bothrops asper, one of the most dangerous snakes in Costa Rica Peter Nijenhuis/Flickr

In 2008, scientists estimated that as many as 5.5 million people are bitten by snakes every year, and that these bites result in up to 94,000 deaths. Anti-venom drugs mean death rates are fairly low in more developed nations, but in countries where access to these medicines is difficult, the chances of dying from a snakebite is far higher. The most snakebite deaths are recorded in India, with up to 46,000 fatalities every year.

3. Snails

giant African snail
Giant African snail - known to transmit Schistosoma mansoni Alexander R. Jenner/CC

Freshwater snails to be precise. They release a larval form of parasite which causes schistosomiasis. These parasites penetrate the skin in infested water and when in the body, the larvae develops into adult worms. Over time, they cause immune reactions and damage to the organs, potentially resulting in liver and kidney failure, as well as bladder cancer. While exact death estimates vary widely, the WHO estimates there could be as many as 200,000 deaths every year from schistosomiasis.

2. Humans

murder dna evidence
Man's inhumanity to man: Human are the second most deadly to fellow human beings  istock

Human beings are the second biggest killer of fellow humans on the planet, accounting for over 400,000 deaths annually. The highest murder rates are found in South America and South Africa. In 2015, El Salvador was dubbed the murder capital of the world and, according to the Associated Press, it recently recorded its first murder-free day in over two years. Humans are however not the only animals on the planet to kill members of their own species. Indeed, chimpanzees have been found to have a murder rate on a similar level to mankind.

1. Mosquitos

Anopheles stephensi
Anopheles stephensi mosquitoes are a major carrier of the malaria parasite in India Reuters

Mosquitoes are responsible for the deaths of over one million people every year, according to the World Health Organisation. This is through disease transmission – primarily malaria, but also carry a host of others, including dengue fever, yellow fever and encephalitis. One popular "fact" is that mosquitoes killed half the people who have ever lived. While we will never really be able to verify this claim, mosquitoes are by far the biggest animal killers on the planet.