I have six 12 week old chicks, which means I have exactly 12 weeks of experience with chickens. Lately, I've noticed a lot of runny droppings. I don't see any blood or worms, and all of the chickens are still running around acting crazy and energetic. The droppings are dark and have the consistency of tar. They smell pretty bad, but then again they never smelled great. I noticed that when one landed on a piece of wood below the perch and dried, it looked kind of like the way chewing gum looks on a subway platform after it's been walked on for a year or so. Could it be something they're eating or symptomatic of something more serious? Sorry for this disgusting and probably unnecessarily detailed post, but i just want to make sure there isn't anything i should be doing or looking for. Thanks!