I have no experience with ferals, but I imagine they have as much grass as they would like in any event, so perhaps that's why they weren't interested in the pet grass. I don't see why they wouldn't enjoy catnip, though.
Wow was the catnip mouse a hit with the male. He was rolling around tossing the mouse into the air and just acting sweet and goofy. The female totally ignored it. She wouldn't even look. Today, however, they both ignored it and prefer playing with a bug they found on the porch.rcat