Similar to bed bugs, mosquitoes leave red itchy marks on your skin with their bites. Unlike lines of bed bug bites, though, mosquito bites will be scattered randomly across exposed skin. A bite from a mosquito will create a bump that can form just minutes afterwards, and their bites can be felt immediately. Mosquito bites are much more threatening than bed bug bites due to their ability to transmit disease. Mosquito bites also tend to heal much faster than bed bug bites.