Everybody needs good neighbours — and for North American red squirrels, having friends next door from year-to-year improves the odds of survival and reproduction.
UK experts studying squirrels in the Yukon, Canada, found that keeping the same neighbours was so beneficial it outweighed the drawbacks of getting a year older.
Squirrels that live in adjacent territories in successive years appear to grow to trust each other — meaning that they end up spending less time defending their territory.
This, in turn, frees up more time to gather food and raise young.
In contrast, living near relatives did seem to not improve the red squirrel's survival rates — but this could be an artefact of their study's sample area, the team said.