Did you solve it? Do your nut with the squirrel puzzle

The solution to today's rodent riddler, and the 2018 challenge

In my puzzle blog earlier today, I set a logic puzzle about squirrels and an arithemetic puzzle about today's date:

1. The Squirrel King has buried the Golden Acorn beneath one of the squares in this 6x6 grid. Three squirrels - Black, Grey and Red - are each standing on a square in the grid, as illustrated.