60. Why do mosquito bites itch? While bees and wasps inject venom when they sting, mosquitoes simply bite to feed on your blood. The bumps and itchiness that follow come from an anticoagulant that the mosquito injects to prevent your blood from clotting, which triggers a mild allergic reaction that includes the typical round, red bumps.

60. Why do mosquito bites itch?

While bees and wasps inject venom when they sting, mosquitoes simply bite to feed on your blood. The bumps and itchiness that follow come from an anticoagulant that the mosquito injects to prevent your blood from clotting, which triggers a mild allergic reaction that includes the typical round, red bumps.