There are more insects in one square mile of rural land than there are human beings in the world.

Certain millipedes give off cyanide gas as a defensive mechanism.

Bumblebees are one of the few insects that can regulate their body temperature, via both solar radiation and via internal mechanisms of "shivering" and radiative cooling from the abdomen.

Female Mosquitos locate their victims primarily through scent. They are extremely sensitive to the carbon dioxide in exhaled breath, as well as several substances found in sweat. Some people seem to attract mosquitoes more than others. Empirical studies of mosquito bites suggest that the risk of being bitten follows an approximately negative binomial distribution. Being male, being overweight, and having type 'O' blood may increase the risk of being bitten. Mosquitoes can detect heat, so they can find warm-blooded mammals and birds very easily once they get close enough.

Mosquitoes are estimated to transmit disease to more than 700 million people annually, and will be responsible for the deaths of about 1 in 17 people currently alive.