Yeah, you do need to set up a way to catch the water that drains out of the cage with a dripper. You can put a large plastic storage container under the cage to catch the water. Just make sure the cage isn't sitting against the bottom of the container so the water doesn't just pool in the bottom of the cage. Not many people suggest this, but you could also try putting a small animal water bottle in the cage and see if they'll drink from that. I did that with my first chameleon (a jackson's) and he took right to it. Every morning when I turned the lights on, he would head right to it and lick the ball on the end to get a drink. You would need to make sure you actually see them drink from it, though, so you know for sure that they will get water from it.