I remember thinking about this classic problem with my friends back in school and tried to work through it again from a physics point of view. It turned out that it is more complicated that I thought:
Why do smaller animals survive falls from larger heights?
I would specifically like to know how physical scaling laws affect the chance of survival of an animal, i.e. we suppose the animals can be modeled as the same shape but every length scaled by a factor $k$. There are two biological factors one has to assume, namely that animals have roughly equal density and the force a muscle can apply scales according to the cross-sectional area it has ($\propto k^2$). I think apart from that one should be able to get away with making reasonable physics approximations. So maybe to reformulate what I mean by the "why" in the question above: can the phenomenon that smaller animals survive falls from larger heights be explained by physical scaling laws?