Pooping is Contagious

Warning: I'm talking about poop here.

I have a theory that my friends who just now have two kids will soon get to test for me: when one kid poops, the other one does.

This has been happening here for a long time now. Sure, they eat the same diet, pretty much, and do the same activities. Though, the diet has changed some--DD eats more starch and meats; DS eats more fruit. But they poop within 2 minutes of each other. Always. Like just now.

I think the smell triggers it.

Like scatological pheromones or something.