Wallnuts

Some weeks ago I blipped a picture of a walnut tree growing across the road from our house and thought that the birds were having them.
Now our neighbours, who have a better view of our front garden, say that they have seen (a family) of 5 squirrels working their way from the fields at the back of the house, through the two gardens, crossing over the road and coming back with loads of wallnuts.  I found these few shells while I was cutting the grass today.  The challenge is on to get a picture of these little nut pickers