Changas or Kissing bugs attack humans while they are sleeping. They are called such because they attack by biting the lips of their victim. These bugs expand as they suck the blood of warm-blooded animals. Thru their bite, a parasite, which is called trypanosome cruzi, is transferred to the victim. This disease kills both humans and animals. Every year 12,000 humans die because of this parasite. A bite from this bug causes welts and rashes to appear on the skin.