A bear cache is a container that is specifically designed to protect food from bears. Hikers and backpackers in areas of the world that are home to bears are at risk from these animals, especially if the smell or sight of food attracts them. Commercial bear cache products are available to buy that people can carry easily and pack food in securely, and that have opening mechanisms that only humans can open.
Food at campsites and in backpacks can emit odors that a bear can find mouthwatering, and so can inadvertently attract the animal. Even if the humans escape unscathed, a hungry bear may destroy valuable property looking for the food. A bear cache is a way for hikers to pack up food in such a way that the smells are reduced, and if the bear finds it, protects the food so it cannot get at it.
Typically, a commercial bear cache is made out of plastic, and is small and light enough for a person to fit in a backpack. It is often smooth and cylindrical, which makes it hard for a bear to grip and rip apart. The closing mechanism on the cache is most useful if it is fiddly enough to need a human to open it, as bears can be dexterous, and can even get into cars. Even though a bear cache reduces the risk of coming into contact with bears, additional precautions such as storing the food away from a campsite, or hanging it midway from a rope between two trees, are often sensible ideas that can serve to protect people from a possibly dangerous or even lethal encounter.
Humans tend to come across bears when they deliberately hike into bear territory for leisure purposes. Bears can also wander into campsites on a foraging expedition. The animals can also travel into villages and towns in search of food, and follow their noses to trash cans and other sources of food. As the animals can be lethal to humans, people generally attempt to reduce their attractive food scent as much as possible. A bear cache keeps human food away from the bears, and bears away from the humans they may possibly endanger.
The animals follow their instincts and tend to make for the most accessible food and the food that has a high energy content. Human food fits both these criteria which can actually make bears into nuisances, and increase the danger to people. A bear that deliberately comes into contact with humans and their food, may need to be euthanized in order to protect people.