This paper seeks to identify the factors which have the greatest effect on gas diffusion rates into animal burrows, and in turn on the maximum size of burrowing animals which may rely on simple burrow ...

particles will spread themselves evenly throughout a liquid or a gas. Diffusion is an essential process in cells. They need glucose and oxygen for respiration, which move into them by diffusion.

Particles - molecules and ions - in a liquid and a gas are continuously moving. Because of this movement, particles will spread themselves evenly throughout a liquid or a gas.