Very odd indeed

[woolybanana]

It seems that these cicadas only come out every 13 or 17 years and then hibernate underground. What possible logic can Nature have seen in this?

http://uk.news.yahoo.com/us-cicadas-invade-south-13-sleep-152022967.html

[Alex H]

A couple of suggestions here http://en.wikipedia.org/wiki/Magicicada

and loads of info here    http://www.magicicada.org/magicicada_xix.php

including

"Periodical cicadas achieve astounding population densities, as high as 1.5 million per acre"

"Magicicada population densities are so high that predators

apparently eat their fill without significantly reducing the population

(a phenomenon called "predator satiation"), and the predator populations

cannot build up in response because the cicadas are available as food

above ground only once every 13 or 17 years."