Could that rash be an insect bite? And what kind of bug ... painful bites, Frye says. A fly bite typically looks like a red welt, and "it often has a little center core to it," Kassouf says.

Bee, wasp, yellow jacket, hornet, and fire ant are the insect stings that most often trigger allergic reactions. But most people aren't allergic to insect stings and may mistake a normal sting ...