Scatter-hoarding spreads risk. Rather than one raidable larder, a grey squirrel makes many single-nut caches, each a few centimetres deep, and relocates them using spatial memory supported by smell. Experiments in which caches are moved show the squirrels return to remembered locations rather than searching at random, though scent recovery matters when snow or rain has intervened.
Recovery is good but not complete. A share of caches goes unretrieved, and buried acorns and hickory nuts are placed at close to ideal germination depth in disturbed soil, so the shortfall becomes seedlings. Squirrels also assess seeds: they preferentially eat white oak acorns, which germinate quickly, and cache red oak acorns, which are dormant longer and store better, and they sometimes excise the embryo from white oak acorns before burying them.
They also cache deceptively. Observations show squirrels performing empty digging and covering motions when watched by potential pilferers, a behaviour interpreted as tactical rather than absent-minded.