I've bought and returned 2 water bottles by 2 different brands because of the same problem. When I got my rats a week ago the day after I brought them home I discovered that they had gone nearly 24 hours without water because water wasn't coming out of the bottle. Luckily, they seemed fine but it could have ended horribly if I hadn't discovered it until later. I've had rats before and never had this problem until now. I wish I had kept those bottles but I must have gotten depressed and thrown them away after those rats died. I'm wondering if maybe it has something to do with my different cage setup. Both water bottles seemed to work fine when held completely straight up and down but for a bottle to fit on my cage properly it needs to be slightly tilted. Does anyone know of a water bottle that isn't so fussy? Could it be because of the way my rats go about using it? I don't like using a bowl for water. They knock it over all the time and poop in it. ???