Hoarding is a general term for a behavior that leads people or animals to accumulate food or other items during periods of scarcity.
Animal behavior 
Hoarding and caching are common behaviors in many bird species as well as in rodents. Most animal caches are of food. However, some birds will also stingily collect other items, especially if the birds are pets. Magpies are famous for hoarding items such as money and jewelry, although research suggests they are no more attracted to shiny things than other kinds of items.
Human hoarding 
Civil unrest or natural disaster may lead people to hoard foodstuffs, water, gasoline and other essentials which they believe, rightly or wrongly, will soon be in short supply. Survivalists, also known as preppers, often stockpile large supplies of these items in anticipation of a large scale disaster event.
Mental illness 
Some hoarding in humans may be a form of mental illness, specifically obsessive–compulsive disorder, where the perceived importance of the hoarded items far exceeds their true value. Humans may lose the desire to throw away unneeded items because of a feeling of attachment to these items. In severe cases, houses belonging to such people may become a fire hazard (due to blocked exits and stacked papers) or a health hazard (due to vermin infestation, excreta and detritus from excessive pets, hoarded food and garbage or the risk of stacks of items collapsing on the occupants and blocking exit routes).
See also 
- Hoard (archaeological)
- Hoarding (economics)
- Compulsive hoarding
- Collyer brothers, rich eccentrics who were noted for compulsive hoarding
- Plyushkin, fictional Russian hoarder
Further reading 
- Tolin, David; Frost, Randy; Steketee, Gail (2007). Buried in Treasures: Help for Acquiring, Saving, and Hoarding. Oxford: Oxford University Press. ISBN 978-0-19-530058-1.
- Neziroglu, Fugen; Bubrick, Jerome; Yaryura-Tobias, Jose (2004). Overcoming Compulsive Hoarding: Why You Save & How You Can Stop. California: New Harbinger. ISBN 978-1-57224-349-1.
- Steketee, Gail; Frost, Randy (2006). Compulsive Hoarding and Acquiring: Workbook. Oxford: Oxford University Press. ISBN 978-0-19-531055-9.
- Steketee, Gail; Frost, Randy (2006). Compulsive Hoarding and Acquiring: Therapist Guide. Oxford: Oxford University Press. ISBN 978-0-19-530025-3.
- Boston University School of Social Work
- "If I Were A Hoarder" , the daughter of a compulsive hoarder writes about hoarding.