When do kittens startpooping?

I have two 5 week old kittens, and one is gobbling up solid food, but I don't see any poop coming out

When do kitties start pooping?

OH I know this one. The mama should be licking their bottoms to get them going and get the "urge" to go started. If they aren't pooping, or are without their mama. You may need to dampen a papertowel and kind of wipe at their little butts to get that started.