i have caught mine drinking a few times. I have only had him for a month and a half. it's funny, i will walk in the room and catch him drinking and he will stop because he doesn't like to do it when anyone is watching and he will sit there hovering over his bowl until i walk away. the times i have caught it are when i have recently (within the past hour or so) changed his water bowl. i have him in a glass tank and my temps and humidity fluctuate a lot, or at least they did when i first got him and was figuring everything out. so i tend to check on him a lot throughout the day, and therefore have found him drinking at least 5 or 6 times since i got him. i wouldnt worry about not seeing them drink, mine usually does it in the evening or the middle of the night