We think this is sand, not sinister eggs, but we also think /u/Slyth011 is wise to ask, because the line between "weird yard stuff" and "weird chicken stuff" is thinner than a feather. When you've got a sand pit in the yard and a hen who's acting off, your brain starts seeing egg clusters where there might just be a gritty clump of dirt. That's the cluck-tastic dilemma of backyard chicken keeping: you become a detective in your own coop, and every speck looks suspicious. If you're dealing with a molting, moody bird right now, you'll want to check out When the feathers fly: beak trimming tips for your molting, moody clucker, because a cranky hen who's losing feathers can leave all kinds of debris that looks foreign. And if you've ever stared at a chicken and wondered "what are you, really?" then Meet my mystery bird: is he chicken, ostrich, or some kind of fowl trick will remind you that weird is normal around here.
You're probably looking at compacted sand or a dried-out clump of grit, not a parasitic egg mass. The description, "very hard and sandy feeling", points to something physical and mineral, not biological. Egg clusters from flies or mites are soft, sticky, or powdery, not rock-hard like a pebble. And since you have a sand pit, the most likely culprit is sand that got wet, packed together, and then dried into a little brick. Your hen might have scratched it into a corner, or it could have formed near the waterer. Either way, it's a relief, not a horror movie prop. But the fact that you're checking means you're paying attention, and that's exactly how you catch real problems early. If your chickens are refusing to coop and winter is coming, you'll want to read When Your Feathered Friends Refuse to Coop: And Winter's Knocking, because a hen who's left outside in the cold can develop all kinds of issues that look like "eggs" but are actually stress-related clumps or frost damage.
The practical takeaway is this: pick up that sandy clump, crumble it between your fingers, and if it breaks apart into ordinary grit and dust, you're done. If it's still suspicious, drop it in a jar of water, real egg clusters will soften and separate; sand just sinks. That one test saves you a week of googling and worrying. What we love about this community is that no one feels silly for asking. You're not chickening out, you're being thorough. So next time you find a mystery clump, remember: sand is sand, fear is real, and we've all been there. The question that matters is what your fowl friend is doing while you're busy investigating.