My 3 year old hen recently did a poop containing a small worm around 0.8 mm in length, she seems healthy and is acting normally and herself. I felt her breast and I can clearly feel her keel bone all the way down her stomach. Her poops are quite smelly and a little bubbly. A few weeks before she did a poo also containing worms, the worms aren't appearing constantly. My other hen who is 4 years old is also skinny, her poops first thing in the morning are really watery but I didn't see any worms in her poops. They were never wormed their whole lives and their diet consists of layer feed and whatever they pick up free ranging in the garden, mostly grass. Should my chickens be wormed or would this problem pass by itself?