i would hang a bird wing as a flag from some mono.. Cat are driven by the vision more than their nose. As it flutters in the wind the cat will come directly under it.
Yep flashy stuff too small Christmas garland on fishing line to get them close to the lure/bait/trap .
I'd like to try the distress bird little cheap $15ish chirper doodads i've read they work great , but are always sold out .