If you’re wondering what’s been causing that noisy racket outside your window all summer, it turns out it’s a call of love — for a creature that looks like it crawled out of a science fiction movie.

George Hamilton, chairman of the Entomology Department at Rutgers University-New Brunswick, said you might not be aware of it but we’re in the final stages of the annual cicada mating season.

“The noise you’re hearing is made by a structure on the females, they vibrate. What they’re doing is they are telling males: Here I am," he said.

“It’s a membrane on their back that they are able, with musculature, to just vibrate very, very quickly. That membrane is actually exposed to the air and that causes the loud noise.”

He said as it starts to get dark, the cicadas wind down their mating calls but “the various types of crickets we have, which are nocturnal, are starting to call.”

Hamilton noted the noise female crickets make to attract a mate is caused by one of their legs rubbing against the side of their body.

“If you think of a washboard that we used to see in country music bands, they scratch the board with their hand. It’s a similar thing.”

He said cicadas usually start making their love call in early to mid summer and they’ll continue until mid September.

“Once they mate, the females lay eggs on the trees. They eventually hatch. The larvae fall to the ground and they borrow into the ground and they feed on the roots of the trees.”

Hamilton said they spend three to five years under ground then finally emerge as adults, mate and then die.

The annual cicadas are not to be confused with the 17-year cicadas that emerge from the ground every 17 years. A batch of those cicadas is due to show up in the Princeton area next summer.

While cicadas may look scary, he said they don’t bite and they are not aggressive.

The only enemy the cicadas have is the cicada killer wasp, which injects a paralyzing poison into their prey. The wasp then drags the cicada into their nest, where the juvenile wasps will enjoy a delicious meal.

You can contact reporter David Matthau at David.Matthau@townsquaremedia.com