First time chick owner & assistant coop builder here..... Can anyone share the size of their hatchway dimensions? I'll have my husband place it a few inches off the ground to keep the shavings inside, but he's asking me how big the "hole" should be.... Our 4 chicks are about 6 wks old & I'm not sure what size they'll be once full grown. I know one of them is a Rhode Island Red & another is (my favorite) those super cute grey/black chicks with the fuzzy feathery feet. Thanks! Once I figure out how to attach a photo, I'd be happy to share a pic!