I have a customer with a BEAUTIFUL emerald zoysia front yard. The back yard however is a different story. It is a myers zoysia, still can't understand why the two varieties... anyhow... the back yard is being TORN APART by coons, opossums, who knows... I know they are digging for grubs. Questions: 1. Is this a sign of higher than normal grubs. 2. How do I get rid of the pests... they back up to a wooded lot... 3. Why aren't they touching the emerald zoysia or the fescue that the dog stays on?