Check the soil, run a finger all through the soil and if you don't see a frog pop it's head out or hop out and start climbing the glass then check the plants, they might just be hiding behind one of the plants. Keep yours dogs out of the room the frogs are in, put a container of water out and a container of food for the frogs and close the door. Stay in the room, if the frogs are still in the room then they will come out for the water and food. I hope your frogs are okay and that you find them in good health (although a bit hungry).