Anti-animal Shell

By casting this spell the druid brings into being a hemispherical force field which prevents the entrance of any sort of animal matter of normal (not magical) nature.

This shell is non-mobile. 

Thus, a giant would be kept out, but undead could pass through the shell of force, as could such monsters as aerial servants, demons, devils, etc. Humans, even though able to use magic, are non-magical, as are dwarves, elves, etc.

The anti-animal shell lasts for 1 turn for each level of experience the druid has attained.