Oops, the can I've been spraying the frogs with is not Benadryl, it is Dermoplast (for sunburn and itch relief) so it's active ingredient is Benzocaine 20%. Still works to immobilize the frogs. Now, I'm sure they feel no pain, either.
I have a little pump spray bottle of Benadryl, and you're right, Ken. It's active ingredient is Dyphenhydramine. Sorry all. I had the two sprays mixed up.