They will figure it out quickly. They are naturally curious and once one of them uses it they’ll all join in. I’d offer both for a few days, but then I’d let them use the nipples. I have 5 gallon buckets with nipples and the water stays clean and I only have to fill every three days or so even in 95 degree weather.Not sure if nipples would work. They are used to open waterer since they were chics. If I introduced that idea would be afraid they wouldn't figure it out lol