Wild Animals have personal space boundaries with each other and humans. The concept is easily demonstrated by these four wild Backyard squirrels, two red squirrels in North Carolina and two Gray Squirrels in Florida - All habituated to me, but each with their unique personalities and reactions. It is important to be aware of personal space with all animals if you want to get along and observe them and generally enjoy Nature more. Personal space violations trigger alert reactions and ultimately fight or flight responses in animals. Violate their space at your peril, respect it and you will be surprised at how your relationships with animals will improve. Especially regarding squirrels unless you raised them from kittens and know them intimately never try to take the initiative to touch or hold them no matter how friendly they may seem, you are now in their intimate space reserved for fellow wild squirrels, their reaction time is so much faster than you can imagine and a simple nip on your finger by them as a warning will result in a mess of a finger. On the other hand, fed and overly spoiled squirrels and most other wild animals such as raccoons and bears will eventually readily invade your own personal space and you'll have an issue of discipline or worse.