It sounds like you are talking about scabies, also known as body lice (although there are many other conditions that can cause bumps as described in the question). They can live up to a month on the body; however, they reproduce, so if they are not treated, they can continue living on the body for a long time. Hope this helps! Dr. B.
The insect with the shortest lifespan is known as a mayfly. This insect barely lives for 24 hours and belongs to the ephemeroptera order.
dragonfly
it is the proventricules found beneath the crop
a firefly
A lightening bug appears to carry a lamp.
whats the comment
An insect that appears to be floating on the surface of water is staying on top due to surface tension. If a couple of drops of soap are added to the water, the surface tension is greatly reduced and the insect will sink. I use this as an example since it can easily be tested around the house. Insects aren't necessary for the experiment since other small objects should work as well.
The mayfly has a twenty-four hour lifespan, sometimes less. Within their life they mate, give birth, and shortly after, die.
surface tension between the legs & water surface
Presence of chitin on the outer surface of the insect body
Cicada
due to surface tension