As long as they can't somehow get their whole bodies in and not be able to get back out, you're good. I'd be more worried that they'll grow too fast and not be able to put their heads in! They just grow too fast. I don't know if you still need ideas for a waterer when they outgrow that, but I'll warn you now: do not use a chick waterer! My four 3 wk. olds spilled 1+ gallons of water every day when I used it. It's terribly messy, and because of that, it needs to be refilled often. I replaced their the chick waterer with a 4 quart feed pan with a piece of clean wood floating in the middle, and, although it isn't perfect, I will never go back. You're pretty funny yourself. You always bring a smile to my face. Good idea! The worrier that I am, I'd be afraid that they'd climb in the bowl and not be able to get back out. But that's just me being paranoid about my ducklings. How long does it take them to outgrow it?