Frogs in the Backyard: Why They Are There, and the Holes

A yard with frogs in it has damp daytime cover, a supply of insects, and water within hopping distance. That is the whole explanation. Everything people find puzzling about them — the sudden appearance after rain, the holes, the noise — follows from those three things.

Frog or toad?

Worth sorting out first, because they use the yard differently.

A toad in a dry flowerbed fifty yards from any water is normal. A frog in the same spot is probably travelling.

What they are eating

Almost anything invertebrate that moves and fits:

• Slugs and snails — the reason gardeners want them
• Cutworms, beetles, earwigs, woodlice
• Mosquitoes, midges, moths and flies, especially around lights
• Ants and spiders

They hunt by movement, which is why a frog ignores a motionless insect entirely. They eat no plant material at all as adults — no seedlings, no fruit, no leaves. Tadpoles are the exception and graze algae and decaying plant matter in the water.

A single adult frog or toad accounts for thousands of invertebrates over a season. That is a real substitute for slug pellets, and unlike pellets it does not also kill the hedgehogs and birds that eat poisoned slugs.

The holes

This is the question that brings most people here, and the answer is usually disappointing: the holes are not frog holes.

Toads do dig — they shuffle backward into loose soil to sit out the day and burrow deeper in dry weather — but what they leave is a shallow depression, not a shaft. A toad found sitting in a neat round hole has moved into something another animal made.

Why they arrive all at once

Frogs do not appear gradually. They turn up overnight after the first warm rain, because that is when they migrate to breeding water and when moving across open ground is survivable.

The other burst comes after heavy summer rain, when temporary pools fill and the young of the year disperse — that is the one where people find dozens of tiny froglets crossing a patio at once. It lasts a few days.

Frogs are also only one of the things calling after dark. If the noise is a dry mechanical chirp rather than a croak, it is probably crickets, and they call at night for a reason.

Living with them

Pets: common frogs are harmless. Most temperate toads carry a mild skin toxin that makes a dog drool and look miserable for an hour. The genuine dangers are cane toads (Florida, Hawaii, Australia) and Colorado river toads (US southwest), both of which can kill a dog — if you are in that range, learn to identify them, and rinse a dog’s mouth out sideways with a hose immediately after contact.

Children: fine, with handwashing afterwards. Amphibians can carry salmonella, and wet hands are kinder to the frog than dry ones.

Mowing: the real risk to frogs in a yard. Walk the area first in wet weather, mow in the middle of a dry day rather than at dusk, and raise the deck.

Chemicals: amphibian skin absorbs what it touches, so anything applied to paving or decking reaches them directly. That is why bleach kills frogs outright and why it should never be used to move them on.

Encouraging them

If you want more — and for a vegetable garden you probably should:

• A small pond with no fish. Fish eat eggs and tadpoles; a fishless pond is the single biggest improvement you can make. Gently sloping edges matter so froglets can get out.
• A damp shaded corner with leaf litter and a log or two left alone.
• A toad house: a broken terracotta pot laid on its side in shade. They get used.
• Longer grass on at least part of the lawn.
• Stop using slug pellets and broad-spectrum insecticide. They remove the food and poison the animals through the skin.

And if you want fewer of them near the house specifically, that is a different job — drier ground along the foundation, yellow bug bulbs, and no standing water within a few feet of the door.