Somethin's eatin' my seedlings... Critter Ridder?

[Jeffrey Ihara]

It's outdoors--I've got two media beds shared with young strawberry plants and mature chard and parsley plants. I put a dozen rapini and lettuce seedlings into one bed last week and noticed that something had dug into the gravel in removing a couple of lettuce seedlings. Yesterday I put over a dozen kale starts into the other bed, and this morning everything is mowed down (but not dug). I'm thinking rats, and I'll leave some snap traps out tonight.

Grrrr.

I also have some piperene/capsaicin "Critter Ridder" granules. Is this stuff fish-safe?