Heat has a tendency to spread into the environment around it. This is why keeping your house warm during a cold winter is extremely hard. To make heat stay inside the house, the building can be insulated.

Most animals also have insulated bodies. Their forms of insulation include things such as fat layers, fur or plumages. Humans wear clothes to provide insulation and to keep their bodies warm. 

Air is a good insulant. This is why many houses are insulated with materials that trap air inside them. These materials are usually called wools, such as glass wool and rock wool.


Insulants prevent heat from escaping into the environment.