Hoarding is a behavior where people or animals accumulate food or other items. Hoarding (animal behavior) Hoarding and caching are common 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 infamous for hoarding items such as money and jewelry. (Contrary to popular belief, research suggests magpies are no more attracted to shiny things than other kinds of items.) One theory suggests that human hoarding may be related to animal hoarding behavior, but substantial evidence is lacking. Civil unrest or threat of natural disaster may lead people to hoard foodstuffs, water, gasoline and other essentials that they believe 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. Other items commonly hoarded include coins considered to have an intrinsic value, such as those minted in silver, or gold, collectibles, jewellery, precious metals and other luxuries. Compulsive hoarding Individuals who meet diagnostic criteria for hoarding disorder experience feelings of anxiety or discomfort about discarding possessions they do not need. This discomfort arises from an emotional attachment to possessions and a strong belief that their possessions will be needed in the future. Possessions will take on a sentimental value that outweighs their functional value. This is no different from someone without hoarding disorder; the difference lies in the strength of this sentimental value and in how many items take on a sentimental value. When discarding items, hoarders may feel like they are throwing away a part of themselves. In severe cases, a house 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).