For anyone interested, I've managed to get the black-headed snake feeding on small centipedes. I had tried crickets and spiders unsuccessfully, but this seems to have done the trick, with the Tantilla at least. I'm going to try small scorpions with the hooknose, as none of the above items worked with that snake. I have also tried millipedes with both, But that failed. So hopefully the scorpions will get the hooknose eating. Otherwise I'll just release it where I found it before it gets too cold around here.