There are more than 1 million kinds of insects in the world. Most of them are harmless, but there are some insects that will readily bite. Some bites are almost unnoticeable while others can cause redness, swelling, pain and itchiness. There are a few types of insects that are responsible for most swelling bites in humans.
Fire Ant Bites
Fire ants are one of the few species of ant that can both bite and sting. Unfortunately, they also are aggressive. Fire ants grasp the skin with their mouths and then sting with their abdomens in a circular motion. Fire ant bites start off as red, raised areas, but they eventually turn into liquid filled bubbles. Swelling is usually there, but mild. If you're allergic, the swelling may be more severe.
Spiders aren't technically insects, but they are responsible for a large percentage of swelling bites. Spider bites can vary greatly because there are so many different kinds of spiders. Generally speaking, spider bites have two very small puncture holes with a red, swollen area surrounding them. Poisonous spider bites will typically ulcerate at the bite site. A larger area around the bite is red and swollen if you're bitten by a poisonous spider. Regardless of the type of spider, swelling is usually immediate and goes away three to five days later. Some poisonous spider bites, such as a brown recluse spider bite, may take longer to heal, or require medical intervention.
Mosquitoes are an insect in the Culicidae family. Female mosquitoes drink blood and commonly bite humans. The most common signs of a mosquito bite are redness, swelling, and itchiness. Often, these symptoms will not appear for up to two days after you are bitten. Conversely, if you are sensitive to mosquitoes, swelling and redness will be immediate and more severe, usually covering a larger area. Mosquito bites usually respond well to hydrocortisone cream or calamine lotion.
Deer Fly Bites
Deer flies are one of the few species of fly that bite. Like mosquitoes, only the female deer fly bites and drinks blood. Deer flies have sharp mouths that they use to slice open the skin. They then insert saliva into the wound to prevent the blood from clotting. The body reacts to the saliva, which causes the redness, itching and swelling. The wound is relatively large and the area of swelling can be quite big.