This insect bite was already starting to improve the next day, a good sign that it wasn't infected.
(c) 2006 Vincent Iannelli, MD licensed to About.com, Inc.
An Insect Bite
Redness, swelling, and warmth can be signs of a simple insect bite or a bite that has become infected.
The fact that this bite got better the next day without any treatment is a good sign that it wasn't infected.
An infected insect bite would likely have gotten worse on the day or two after the bite first occurred.

