To make a very, very long story short:
My father feels quite protective of the herbivore and aviarian wildlife on his property, so when he found that the duck family created a nest and laid some eggs, he built a fence around it to protect it (with the opening facing to the lake).
However, shortly afterwards, he heard the mother duck screaming her head off, and he found that all of the eggs had been broken and my grandmother’s cat was leaving the scene. He had to be talked out of shooting the cat.
I find it hard to believe that cats would have any reason to break eggs. Do they eat eggs? Isn’t that what mongoose, rats, shrews, oppossums, etc. do?
My grandmother isn’t around, so this cat has been without his lifelong owner. He’s very, very lonely as a result… he’s got a strange attachment to Dad and follows him around outdoors but Dad just doesn’t like cats and doesn’t return any affection. The duck stayed in her nest as he built the fence, so could it have been a strange jealousy issue here also?