Why Do Squirrels Bury Nuts? And How They Find Them Again

Tree squirrels do not hibernate, and the nuts they depend on all ripen within a few weeks. Burying them is how a few weeks of abundance becomes six months of food — and why your lawn is full of small neat holes in October.

Scatter-hoarding, and why one nut per hole

A grey squirrel may make several thousand caches in a single autumn, almost all holding a single nut, spread across its whole range.

That looks inefficient until you consider what it is defending against. Squirrels steal from each other constantly, and so do jays, mice, chipmunks and deer. One big hoard is one big loss. A thousand single caches means a thief who finds one has found one nut.

How they find them again

Two systems working together.

Spatial memory does most of it. Squirrels remember cache positions relative to landmarks — tree trunks, rocks, fence posts, path edges — with real accuracy, and they revisit them purposefully rather than searching randomly.

Smell does the last few inches, and only under the right conditions: damp soil and a shallow cache. Under dry ground or deep snow, scent does not carry and memory carries the work.

There is also good evidence for chunking — organising caches by nut type, so that all the hickories are in one broad area and the acorns in another. It is the same trick people use to remember a shopping list by category.

The faked burial

One of the better-documented pieces of animal deception. A squirrel that believes it is being watched will:

1. Dig a hole
2. Lower its head into it
3. Push soil back over and pat it down carefully
4. Walk away — still carrying the nut in its mouth

They do this markedly more often when another squirrel or a person is nearby than when alone, which is what makes it deception rather than carelessness. The real cache gets made somewhere else, unobserved.

It follows that watching a squirrel bury something is a poor way to find it.

The forest-planting side effect

A significant share of caches are never recovered — forgotten, stolen, or the squirrel dies first. Each one is a nut planted at exactly the right depth, in loose soil, away from the parent tree.

Oaks, hickories, walnuts and beeches all rely on this heavily. Acorns are too heavy to be carried by wind and rot on the surface, so a large share of oak recruitment comes down to squirrels and jays mislaying things. In practical terms squirrels are one of the most effective tree-planting animals in temperate forests, entirely by accident.

When it is your lawn and your planters

Pots of loose soil are ideal caching ground: soft, well drained, easy to dig, easy to relandmark.

What works:

• Coarse gravel as a top dressing on pots
• Chicken wire laid flat over the soil surface, planted through
• Pine cones as a mulch — awkward to dig through
• Clean up spilled birdseed. A feeder supports squirrel numbers far beyond what the yard would naturally carry, and everything else follows from that
• Plant bulbs deeper, and cover the bed with wire until the ground settles

What does not: removing the squirrel. A vacated territory with food in it is refilled within weeks, and in most places relocating grey squirrels is regulated or illegal anyway.

The autumn timetable

• Late summer: feeding hard, building fat
• Autumn: intense caching, most of the digging you notice
• Winter: retrieval, plus bark, buds and whatever the feeders give up
• Late winter: the leanest period — cache stocks are down and nothing new has ripened
• Spring: buds, shoots, flowers, and the first litter of the year