Big bugs eat little bugs. And sometimes it works the other way around. That's how the food chain works. So why not set the table for natural enemies to feed on your problem yard and garden insects?

The notion is translating into some exciting -- and unusual -- products for sale.

"Defenders of the garden, they call them," said Maxcy Nolan, an entomologist with the University of Georgia Extension Service.

Certain weevils, nematodes, ladybugs and other creatures prey on other insects and plants. The idea is to release them into your yard or garden to control weeds, fleas, beetles, grubs and other pests. And research is showing that in many cases, they work.

One new control method is to spread nematodes on your lawn to control fleas. Nolan investigated the claims.

"I don't know how available it is here," he said. "But you can apply nematodes to your yard and they are effective against flea larvae. Many insects in some stage of their life cycle are affected by some nematode."

But not just any nematode will do. Parasitic nematodes can control Japanese beetle grubs, weevils, borers and flea larvae. You can order them in packages of 10 million.

"They're fairly expensive," Nolan said. "But for people who want to go this route, cost doesn't seem to bother them."

The key is to apply the nematodes when the ground is moist and warm. The best time is May or June, Nolan said. Check with your local garden center or a mail-order catalog to order parasitic nematodes or other beneficial insects.

"They're getting more and more widely available," he said.

The scientific work that supports these claims has only been completed in the past few years. But it does show that "the right nematodes applied properly will control flea larvae," Nolan said.

Flea-eating nematodes are just one example. To learn more about this natural process, scientists are studying the tiniest links in the food chain throughout the world. They're looking for ways to rely more on nature and less on pesticides.

Since different geographic areas nurture various species of plants, insects and animals, researchers are finding some unusual natural controls.

Some people fear releasing insects to control one problem may create another. For instance, some forms of nematodes attack field crops every year, forcing costly chemical controls. But Nolan said research doesn't support that fear when using the proper one.

"When you artificially produce a living organism to be used against another living organism, it cannot perpetuate itself," he said. "You can use it in a given environment. But as soon as it destroys or consumes the other organism, if it doesn't have any more food, it dies."

Some argue that using natural controls is messing with the natural order. But Nolan said it's just speeding it up.

"Even though Mother Nature has checks and balances, sometimes things get completely out of hand before she applies her check for balance," Nolan said. "People can't always wait that long."