Native habitat: Sub-Saharan nations (Africa)
Death toll: Every year 250,000 to 300,000 people are left to suffer because they go undiagnosed and untreated
Why you should be terrified of them: This fly feeds on the blood of mammals resulting in the body slowly being destroyed by a parasite.

The Tse Tse fly belongs to the family of the house fly. This insect carries a parasite that travels through the flesh if bitten, leading to death. This death is referred to as the sleeping sickness resulting in certain body parts shutting down and the person becoming comatose. The disease is easy to treat, but because of the expensive medication, several go untreated and end up dying.