To be fair, root comment only says "mice will run 10k a day" but it isn't 100% clear what that 10K actually refers to, could be steps, could be meters.
My physics teacher always assumed it was potatoes when the SI-unit was missing
In the running context, a 10K means 10 kilometres.
That's awfully European of you, what if the mice are from the US?
Means the same thing here.
“I ran a 3.1mi this morning and I feel awful!”
No, distance events are still referred in kilometers in the US.
US runners also typically train for kilometer races at distances shorter than half marathon.