Just about anything can cause an impaction if they gorge on too much of it.I’ve been reading that sand could cause this?
Can you post a pic of the sand, with a quarter for scale?I went to my local sand and gravel company and told them I needed sand for my coop, because I bought bagged, construction sand, and it was way too fine. He knew exactly what I needed, and brought me some. It's perfect! I'll never buy bagged sand again. And it cleans like a dream!
How big of an area do you have the sand and is it exposed to rain/snow?