Just because your squirrel grunts does not necessarily mean that he is a male. I know some females who grunt.
Try this simple experiment...

Note for three days the direction that "One Eye" is looking while he feeds. Record these observations.

Then after three days if you find that "One Eye" directs his good eye towards the sky in look out for deadly hawks, then he is a female.

Conversely. If "One Eye only pretends to feed, and is oblivious to deadly hawks, and has his one good big brown eye focused on you in admiration, then "One Eye" is a male and you may call him Tom.

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