For those asking...
Water tastes like...water! It's just not nice.
Also, when I drink water, it quenches my immediate thirst, but soon after I feel thirstier than i did before. I know I am rehydrated, but it doesn't feel that way. A little bit of squash or juice and my thirst feels quenched.
My kids drink milk when they were born, breast milk mainly, we moved on to cows milk and occasional formula. It is a lot sweeter than water.
At 6 months i introduced a little bit of water with their meals.
DS1 has never liked or drunk it. By the age of 2 or 3, he had discovered other drinks exist. In year 5 and 6, used to be sent home from school with headaches. A large drink of something and his headache would disappear.
DS2 drinks water, doesn't really like squash. Still prefers milk.
DS3 didnt really drink at all, with resultant constipation, pant messing, and bed wetting. He discovered Apple juice age 3 and 6 years later I think we might be there. He will now drink water.
DD loves water.
We still buy an obscene amount of milk!
The poor little mites won't dehydrate just because they got a bottle of water.
You've not read these threads before have you? They don't dehydrate because they end up in hospital on drips. (Next time, their parents give them something they will drink)