I would try to get a rolling magnet to go over your soil and bedding. They are used to pick up nails after roofing a home or building. We have used them a lot at home. I hope that your hen recovers.
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https://www.harborfreight.com/22-in...Z5j2Nicg9MDesyGwF6njXP2erM6gF6tIaAnayEALw_wcB