When millions of cicadas emerge across the eastern United States for a rare mating season, they will appear as tasty morsels to pets who could get sick from eating them.
 
The cicadas are protein rich but their hard outer shells can cause vomiting, constipation and intestinal blockage in cats and dogs. The cicadas are delicious treats for dogs and cats.
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Millions of the large, red eyed insects will soon emerge from the ground for a once every 17 years mating dance lasting well into June.  The cicadas will climb into trees and shed their shells to reveal their wings. Males will attract mates through a loud buzzing sound.  The approximately 1.5 inch long cicadas, combine all the stuff that particularly dogs like to chase.  They are a kind of flying pet toy. They are loud, slow moving, often low flying.

To keep your pets safe keep them  indoors, securing screens and holding tight to dog leashes outdoors.
 
What is a Cicada?
Cicadas are flying, plant sucking insects, their closest relatives are leafhoppers, treehoppers, and fulgoroids. Adult cicadas tend to be large about 1.5 inches long with prominent widen set eyes, short antennae, and clear wings held roof-like over the abdomen. Cicadas are probably best known for their conspicuous acoustic signals, which the males make using specialized structures called tymbals, found on the abdomen.

All but a few cicada species have multiple year life cycles, most commonly 2 - 8 years.  In most species, adults can be found every year because the population is not developmentally synchronized, these are often called annual cicadas. In contrast, the cicadas in a periodical cicada population are synchronized, so that almost all of them mature into adults in the same year. The fact that periodical cicadas remain locked together in time is made even more amazing by their extremely long life cycles of 13 or 17 years.
 
Periodical cicadas are found in eastern North America. There are seven species, four with 13 year life cycles, and three with 17 year cycles. The three 17 year species are generally northern in distribution, while the 13 year species are generally southern and mid-western.  Cicadas are so synchronized developmentally that they are nearly absent as adults in the 12 or 16 years between emergences. When they do emerge after their long juvenile periods, they do so in huge numbers, forming much denser aggregations than those achieved by most other cicadas. Many people know cicadas by the name 17 year locusts or 13 year locusts, but they are not true locusts, they are a type of grasshopper.
 
Are cicadas dangerous?
Cicadas are harmless. Cicadas do not bite or sting and have no known toxic chemicals. Adult cicadas are usually a nuisance by their sheer numbers and loud piercing call.  If a cicada lands on you it does so only because it finds you to be a convenient place to land, unless you happen to be using a lawnmower or weed-whacker, in which case it might be attracted by the sound.   When handled, both males and females struggle to fly at first, and males make a loud defensive buzzing sound that may startle but is otherwise harmless. Periodical cicadas are not poisonous to animals or humans, nor are they known to transmit disease.

Cicada juveniles are called nymphs and live underground, sucking root fluids for food. Cicadas spend five juvenile stages in their underground burrows, and during their 13 or 17 years underground they grow from approximately the size of a  ant to nearly the size of an adult.
 
In the spring of their 13th or 17th year, a few weeks before emerging, they may build mud tubes that project three to five inches above the soil, apparently to escape wet or saturated soils. These tubes are often mistaken for the tubes that crayfish build.  On the night of emergence, nymphs leave their burrows around sunset, locate a suitable spot on nearby vegetation, and complete their final molt to adulthood. Shortly after molting the new adults appear mostly white, but they darken quickly as the exoskeleton hardens. Sometimes a large proportion of the population emerges in one night. Newly emerged cicadas work their way up into the trees and spend roughly four to six days as adults before they harden completely, they do not begin adult behavior until this period of maturation is complete.
 
After they mature, the males begin producing species specific calling songs and form choruses that are sexually attractive to females. Males in these choruses alternate bouts of singing with short flights until they locate receptive females. Adult cicadas will die within days if not provided with living woody vegetation on which to feed. Cicadas feed from a wide variety of deciduous plants and shrubs, but usually not from grass.
 
After 6 to 10 weeks, in midsummer, the eggs hatch and the new nymphs drop from the trees, burrow underground, locate a suitable rootlet for feeding, and begin their long 13 or 17 year development.