Thanks for the reply!

Oops, I made a mistake: I meant brown for house cricket and black for field cricket.

The black crickets, to my eye, look like the field crickets that a Google search throws up, but without the wings. I've never seen anything wing-like on any of these feeder crickets. I'm not sure if they're just not mature enough, or there's something else going on.

The black crickets don't seem too aggressive, and anyway I'm bowl feeding the frogs, so they just hop in, eat, and jump out again. When the crickets are being raided, it seems their instinct is just to freeze until the frogs lose interest in them.