Dust bunnies also called dust mice, are small clumps of dust that form under furniture and in corners that are not cleaned regularly. They are made of hair, lint, dead skin, spider web, dust, and sometimes light rubbish and debris, and are held together by static electricity

Electrostatics

Electrostatics is the branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges....

 and felt

Felt

Felt is a non-woven cloth that is produced by matting, condensing and pressing woollen fibres. While some types of felt are very soft, some are tough enough to form construction materials. Felt can be of any colour, and made into any shape or size....

-like entanglement. They can house dust mites

House dust mite

The house dust mite is a cosmopolitan guest in human habitation. Dust mites feed on organic detritus such as flakes of shed human skin and flourish in the stable environment of dwellings. House dust mites are a common cause of asthma and allergic symptoms worldwide...

 or other parasites

Parasitism

Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...

, and can lower the efficiency of dust filters by clogging. The movement of a single large particle can start the formation of a dust bunny.

Dust bunnies are harmful to electronics, as they can obstruct air flow through heat sinks

Heat sink

A heat sink is a term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or a liquid. Examples of heat sinks are the heat exchangers used in refrigeration and air conditioning systems and the radiator in a car...

, severely raising temperatures and shortening the life of electronic components.

A trademark for "Dustbunny" was registered in 2006 for the "Dustbunny Cleaner", a robotic ball with an electrostatic sleeve that rolls around under furniture to collect dustbunnies and other material.

Dust bunnies have been used as an analogy for the accretion of cosmic matter in planetoids.