In some parts of the country, cicadas with 17-year life cycles are returning, too. The noise emanates from males trying to attract females, says Phil Nixon, an entomologist at the University of Illinois. Last year, Illinois experienced the return of the 17-year cicada, which generally dwells in the northern half of the country. Both life-cycle cicadas are expected to return this summer in Missouri and Oklahoma. They have clear wings with orange veins.
Periodical cicadas have a higher-pitched sound and sing during the day.
As they emerge from the ground, the 13-year cicadas climb trees or fence posts, where they shed their nymph shells to become winged adults. They do little feeding, preferring to spend their days in reproductive activities. Eggs are mostly laid during the last 10 days of the female's life, Nixon said. They make slits in twigs or branches to insert their eggs. Nymphs that hatch from the eggs drop to the ground, burrow into the soil and find tree roots to feed on until they emerge 13 years later.