Bare Patches in Bermuda

Take a look at these bare patches in the bermuda lawn below.  I see patches like these very frequently, any idea what causes them?  The second photo is a close up of what is causing the problem – rabbit droppings.  The droppings are so acidic they will burn holes through bermuda.  Possible solutions include scattering the droppings with a rake or spraying the area with fox urine (yes, it’s really fox urine).