We have found that chickens like to scratch their feeders as much as the grass etc.
To solve this problem just get a couple of galvanised tent pegs and push one in the ground each side of the feeder and clip them over the respective edge to stop the chickens from tipping them over and wasting the food, and making a mess.
This method also allows the pegs to be moved with the feeder, of course you can always use a hanging feeder but these are not always a viable option.
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