Question: What cause animal to shed their coat??

Clare Harding answered on 12 Nov 2014:

For mammals, loosing hair is dependent on the amount of light from the sun. We have a hormone called melatonin which is produced when there is sunlight and increased temperatures (like when winter becomes spring). This has lots of effects (including helping us go to sleep and wake up, teenagers are not very good at producing this hormone so they find it harder to get up in the mornings!)

In animals, this hormone also means that animals start to loose their winter coats so they dont overheat in the summer. There are also lots of other animals that shed their skin or exoskeletons but these are caused by different things, in mammals it is mostly sunlight!