We all know those pesky insects are annoying, but they’re a lot more dangerous than you think. Even though they bite you and leave an itchy welt, did you know they could also transfer deadly diseases? Dengue, malaria, and the chikungunya virus are several diseases transmittable by a mosquito bite. These viruses will leave you with a nasty fever, body aches, headache, rash, and all sorts of other horrible symptoms. There are four strains of the dengue virus, and if you catch it a second time, it could be deadly. If you catch any of these viruses, it’s a good idea to head straight to the hospital instead of waiting it out (via Science Focus).