Mouse filmed tidying up man's shed every night
bbc.com
bbc.com
Mice have "mice paths". They locate the more direct routes from its home to the feeding areas and travel this routes often. This paths are a 3-D maze (can run over or under obstacles), and they memorize it by heart.
If something happens they will jump to safety fast light, without even thinking about it. They will use a sort of escape algorithm ("jump left, climb, jump, jump, fall, jump right, hole") and don't need to see the path. Can retreat in absolute obscurity and experiments show that even blinded mice manage to do it without landing on sharp tools. They will even jump over ghost obstacles if removed by researchers in the middle of the night.
This mouse is not tidying up; Is keeping its safety route safe. Those annoying random obstacles could became fatal if stand in the way. This way, it does not need to reset and memorize a new (and longer) escape route each night; and also reduce the risk to be ambushed by predatory rats.
I think the real money in brain implants is putting them in animals to make them do things like this.
Explanations like "it thinks it's building a nest" (mentioned in related [1]) on the one hand or "play" on the other (my own) do seem very unsatisfying. Do they really not realize there is no resultant nest, and have they been observed using it as a nest subsequently?
If the price comes down enough you’d mostly see it in animal husbandry, large livestock, and breeding exotic large pets like pandas.