Under 3 = nap. Over 3 = quiet time. This lasts from about 1pm to 3pm. Or, immediately after lunch for two hours.
During quiet time, we play.... quietly!! Lol. Books, games, puzzles, we may watch TV or a movie. But not running, shouting, jumping, etc. (We don't usually do that inside anyway, since we use "walking feet" and "indoor voices" while in the house)
This is explained to parents, and is not negotiable. I need that break!!
In general, when parents have issues with this, it's because the sleep habits at home are not great.