We keep our bird/squirrel food in big plastic cans. We have to keep the garage door shut because
the squirrels know where it is and if they can't get the can open, they gnaw holes in them. We had to screen the vents into the garage because small squirrels could squeeze through. When we lived in Texas, we had a deck across the back of the house and a big cabinet where we kept the food. Raccoons could get the doors of the cabinet open, don't know how in the world they did it. They are such clever animals.
I loved your squirrel story, so sorry he was killed. We've had one or two that have become quite friendly, just not that friendly. But then because of mosquitoes, etc, there's usually a screen between us and nature when we sit outside. I hate that.