Mosquitoes are considered the world’s most dangerous animals, responsible for approximately 725,000 deaths annually, according to BBC Wildlife. Only female mosquitoes bite, as they require blood to nourish their eggs. They spread diseases such as malaria, causing the majority of deaths. Mosquitoes also transmit dengue, yellow fever, and Japanese encephalitis, posing significant global health concerns. Preventative measures include mosquito nets and insecticides for travelers to endemic areas.