What kind of bug bite is this? Fleas? Today, I need to sit in the grass (park lawn) to take pictures, and I was bitten a lot by this small one.

Mosquito.

Almost everyone has the unpleasant thing of being bitten by mosquitoes. Actually, it should be said that it was bitten by a mosquito. Mosquitoes cannot open their mouths, so they don't bite the skin. In fact, they pierce human skin with six needle-like structures. These short needles are the center of mosquito feeding mouthparts.

& gt These short needles suck human blood like blood-drawing needles; Mosquitoes also excrete saliva containing anticoagulant to prevent blood coagulation, so that they can be safely eaten. Mosquitoes ate, drank and floated away, leaving behind an itchy bag!