When chickens are healthy, they look it. Their coats are shiny, they are not hen pecked, their combs (Isaa Browns) are bright and upright.
Sometimes backyard gardeners don’t realise that in fact their chickens are actually on the unhappy side of life. Sometimes food is given only once a day and then the chickens are left to fend for themselves. The idea being that they will scratch around and find lots of worms, centipedes, termites and slaters. But this is hardly ever the case unless you as a backyard gardener have made a real effort to provide habitat for these invertebrates. Even with a heavy layer of mulch on the ground, there are very few invertebrates in the chicken run unless you go to a bit more effort.
Moisture is a key ingredient in attracting invertebrates to where you want them. Mulch helps to retain moisture but not as effectively as other sources.
For example bricks, thrown out marble slabs, logs and wooden beams work best (as well as garden pots etc) . In part because these sources unlike the mulch which is being turned over repeatedly by the chickens, stay put until the backyard gardener comes and turns them over. Hence moisture is retained very well.
When the bricks, beams, marble slabs are turned, worms and slaters and jumping invertebrates are released.
In winter more than summer, life abounds because there is more moisture in and on the ground.
It takes about 10 seconds for my flock of three to eat and finish off what they find on each turning. And it is as a result of me turning the logs, bricks etc for them that they can access the food. It takes very little time, a days work or less for chickens to obliterate the run that they are in and for the run to become a dust bowl unless it is managed. A heavy mulch is always beneficial because even if it cannot support invertebrate life on its own for long, it helps keep chickens feet clean and dry and reduces flies to the run.
The compost and worm farm, is an important asset which I have located in the chicken area because it provides a ready supply of worms, slaters etc for my chickens to feast on.