Generally speaking, they lay about 50 to 100 eggs and these are laid in a white silk and sack.

And after the baby's hatch, the mother just about immediately lays another set of eggs.

And these are what are known as trophic eggs.

These are eggs that are never going to hatch and they will serve as food for the spiral wings.

This is Dr. Bill Schott, a professor of biology at Long Island University and a research associate in residence at the American Museum of Natural History.

He's telling us about the black lace weaver spider.

It's common in the United States. You've probably seen one before.

You probably have one somewhere in your yard right now.

They're hard to describe because they look like a spider.

They're about half an inch brownish black and color. No unusual markings. No beautiful webs.

So when the spiderlings hatch, they immediately set about eating the eggs, the trophic eggs that their mother has laid.

Now spiders and a lot of other arthropods, animals that have an outer cover and they have their skeletons on the outside of their bodies, like shrimp or lobster or scorpions or in the wild.

The only way that they can grow in size is to shed their outer, that's the mold, they're cuticle.

So after their first mold, they're pretty much out of food.

So they've gone through the trophic eggs that their mother has produced.

And that's when they do something really kind of strange.

The mother basically thrums on the web, drawing the babies too, or it's like she drums on the web a bit.

And they are attracted to that vibration of the web and they swarm all over her.

Spiders are all about vibration. And so what she basically does is she's plucking on her silk and attracting the youngsters to come to her.

This is Dr. Linda Raior. She's a senior lecturer and senior research associate at Cornell.

And her specialty is the social lives of spiders.

They respond to the movements and move in toward her as a group and start feeding.

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