It drains beautifully also. When we had a tropical storm a few weeks ago the litter was quite saturated at first, but within a couple hours it was just damp. My feet made prints, but the chickens ran across the surface, not sinking in at all!
After the chickens decimated the grass in the chicken run, I first covered the dirt with wood chips, but soon afterwards converted the entire chicken run into a chicken run composting system. For me, that was the best decision I have made with my chickens.
I dump all my organics into the chicken run, such as grass clippings, leaves, weeds from the garden, etc... This time of year, with all the leaves dumped into the chicken run, the litter is about 18 inches deep. Over winter, that will compost down to about 12 inches.
Not only can I walk on the chicken run litter without any problem, but, like you mentioned, the chicken have no problem at all walking on the composting litter. Nodody gets muddy walking all that litter in the run.
Better yet, the chicken run litter is full of natural life. My chickens are constantly scratching and pecking in the litter finding tasty bugs or juicy worms to eat. They love the compost litter in the run. In the non-snow months, my commerical feed bill is cut in half because they find so much good stuff to eat out in the chicken run. That's a win-win.
yes, the litter is constantly disappearing, breaking down as expected, intended.
That's black gold compost in my book. Over the past 3 years, I have built up so much compost in the chicken run that I can harvest bags and bags full of rich compost and never run low. This spring I sifted out about 24 cubic feet of compost from the chicken run for my raised bed gardens, and I estimate that I harvested less than 10% of what was available.
With my cement mixer compost sifter, I can sift out $60 of compost (price of compost 3 years ago) per hour with little effort. I don't know what the current prices of compost are, but I doubt they went down in price.
I tell people I have composting chickens and get fresh eggs as a bonus. I harvest hundreds of dollars of compost from the chicken run composting system every year to feed the garden and grow people food, and the excess fresh eggs we sell cover the cost of the commercial feed bill for the chickens. What's not to love about having a backyard flock?