Any gardener or homeowner with an attic or an interest in feeding birds will tell you it’s a daunting instance of Man vs. Nature.
An unequal contest, really. On one side, you have a creature capable of scrambling both up and down vertical surfaces (its back feet can rotate 180 degrees), tight-roping across clotheslines or fences and sliding headfirst down wires, a creature that can launch into the air, cling tenaciously, and use its dexterous claws and sharp teeth to have its way.
Above all, you have a highly-motivated creature with a single-minded determination to sniff out, seize and literally squirrel away food, and a will to squeeze its way into cozy nesting spots.