| The fur of a dassie rat is soft and silky, but there is no underfur. |
| Gray wolves have a dense underfur layer, providing them with excellent insulation against cold conditions. |
| The fur of sea otters is very dense with an insulating underfur and a layer of long guard hairs over the top which trap a layer of air, adding further to the insulation. |
| When you look at fur, especially the really dense fur of mammals, you look at that underfur, and it looks like down. |
| The fur is composed of short, soft underfur covered by shiny guard hair. |
| The pelage consists of a dense, soft underfur overlaid with dark and glossy guard hairs. |
