Totally not music post!!

[Greeny]

Crossbow?

[Farmjazz]

The best solution I've found, (and I've tried all kinds of remedies), is ground cocoa shells. The cats don't like the feel of them on their feet. You spread them over the garden bed as a mulch. They come in a bag, ready to go, at your local nursery. They smell great, too!

[StevieM]

I'll try almost anything.
A crossbow's quieter than a shotgun I suppose.
I had a dog 'till about 2 years ago, soppy bugger was either scared of cats, or wanted to play with them Still miss him
Could get another one, but it'll have to big and fierce with lots of big gnashy teeth.

[Sprocket]

I agree with one of the early posters, get a cat. Cats are so low maintenance, I dont know how you dog owners do it...and outdoor cats are awesome!
They are VERY territorial and wouldnt think twice about mangling another trespassing cat...whereas a dog aint even gonna get close.

But I think your "problem" isnt really a cat...I cant imagine a cat going through all the trouble of digging up seeds...especially as a source of food...itd almost have to be another animal, like an armadillo or similar.

[StevieM]

Yep, definitely cats. They use the seed bed  as a loo, they don't care what's in it.
If it was an armadillo they'd be after the ants. Maybe there's one that likes to eats cats instead? I want one!!!!
Anyway, these don't look half starved, they're just nasty brutes that crap anywhere except their own gardens, and I caught them a few times waiting to pounce on Blackbird chicks that hatched about 5' off the ground in ivy growing in our garden. Chased them off a few times. They just kill for fun, not hunger .
Dogs actually like to have a decent owner, and are loyal, cats just put up with where it's most comfortable and they get fed.
Got the idea I'm a dog, NOT a cat person???