Will they come to beaver castor? Curious. Thanks

Occasionally yes but not a reliable attractant for otter.
A lot of other species are more attracted to castor than otters are,maybe because otters are exposed to the scent of beaver in their everyday travells.
It s more of an ambient scent in their natural habitat.

Thank you

I wonder if curiosity lures would work on them.

Maybe some Beaver Plus and a visual of a fish.

A large silver fishing spoon or woodpecker flasher in the wind might interest them too. They’re pretty smart so it might chase them away too. Intelligence could work either way with them.

Their droppings..

Every time I find a toilet I take a sandwich bag of scat to place in another otter family’s toilet, seems to keep them around the toilet longer as they investigate the area. I’ve used many different lures, Cavens otter lure supreme is my favorite and they still swim right past it sometimes. I get coyotes and fishers working my sets from the dry ground side a lot. But yeah otters can be tough to pull in. Good luck.