Some people think hoarding behaviors are related to animal hording behaviors, like birds collecting items.
I didn't know that! That is really interesting. 
There isn't a whole lot of evidence for it though. Most animals horde, or cache, food. 
I can see that hoarding can make someone feel safe if they grew up with almost nothing. Squirrls are cute with thier cheeks full of food.
They definitely do! Most animal hoarding is done by birds and rodents, and squirrels are a type of rodent!