There are several garden creatures that will help rid your garden of pests. Though some can also be considered pests, they usually help more than they harm.

Ground Beetles

Scurrying, big black beetles that are more often seen at night. Both adults and their larvae are useful predators of slugs, caterpillars and aphids.

Hoverflies

A group of true flies that look like bees and wasps. Their greeny brown larvae, 1/2 inch (12mm) long, feed on aphids and can eat up to 100 a day.

Hedgehogs

They eat caterpillars, beetles and slugs at night. If they visit your garden, put out tinned dog food rather than milk. A log pile might provide suitable shelter and a place to hibernate.

Rove beetles

This group includes the distinctive looking devil's coach horse beetle. Both adults and their larvae are active predators of soil grubs, insects and slugs.

Ladybirds

A single larva can eat 500 aphids so they are worth encouraging. Two-spot and seven-spot ladybirds are the most common.

Wasps

Many solitary wasps are beneficial against aphids and caterpillars. Provide egg-laying sites by drilling .2 to .4 inch (5-10mm) holes in posts.

Centipedes

These fast-moving creatures eat all types of small insects. Do not confuse them with the slower millipedes, which feed on plant roots. Centipedes have one pair of legs per body segment.

Earthworms

Worms pull organic matter into the soil, which saves you having to dig it in. They also open up the structure of the soil, aiding drainage and making it easier for plant roots to establish.

Bats

Night feeders of nocturnal flying insects. Encourage them with bat boxes where they can roost. They are under threat, mainly due to poisons in the chemical treatment of roof timbers.

Frogs, toads and newts

These amphibians prey on slugs, flies and other insects. They need a pond in which to breed and will return to it year after year.

Lacewings

Adults are bright green and have large see-through wings and long antennae. Adults and their larvae feed on aphids. You can buy chambers to protect them and lacewing eggs.

Slow-worms

These legless lizards, up to 11.8 inches (30 cm) long, eat the small grayish slugs that feed on the soft growth of young plants and vegetables.
Slow Worm (Anguis fragilis)
AlasdairJames/iStockphoto
Slow worms will eat the slugs that feed off of young plants and vegetables.