im feeding them to mine, no problems yet its been everyday for a couple weeks, 6 pygs total eating them, careful not to over feed, and keep em well hydrated
Probably climb out of a bottle cap...but might hold them for a little while. Try a plant pot dish or something a little deeper with steep smooth edges.
I use a disposable cup cut in half/quater. but have also taken to now using a deep ashtray that is clean. after a while the cups and containers tend to get a build up of dirt and the calcium/vitamin powders. but the glass on a ashtray is easily cleaned, and dosnt topple over and result in mealworms everywere, and hiding.
use something NOT clear and low, place in a central location untill you can find a suitable glass container, ashtrays work very well for all the reasons mentioned above.