Lorraine, have you been getting many sunny days lately?

This may sound crazy but I've noticed this about Storm recently. When it's been dreary and rainy for several weeks, he tends to get moodier and more grumpy and he'll lash out at his brothers much more. When he finally gets to see the sun again his mood is much better and he seems much happier. I know that sun deprivation affects people too and can cause depression but I never thought that it could also affect animals in a similar way.