How do chickens know they should eat oyster shells?

[deacons]

This has always perplexed me. Crushed oyster shells are not a naturally occurring food source in most regions, so how do the chickens know they should eat it to satisfy their calcium needs?

 

[pdirt]

If they're in egg-laying mode, they need extra calcium for the egg shells and some sort of instinct will drive them to find it. I'm not sure how they know this, but my guess is it's based upon smell.

It matters not what kind of calcium you might give them...oyster shells, eggs shells, crustacean shells, limestone, etc. They will eat it if they need it. Some say they get calcium also from the exoskeleton of some insects.

I suppose there were some chickens of yore that lived on the coast somewhere that had access to shell fish such as oysters.

 

[deacons]

I was wondering if smell could be related to it.

It makes sense that in the "wild" they would use things like eggshells or potentially insect sources. Oyster shells work great for my flock- it just seems really random!

 

[Ol Grey Mare]

If they're in egg-laying mode, they need extra calcium for the egg shells and some sort of instinct will drive them to find it. I'm not sure how they know this, but my guess is it's based upon smell.

It matters not what kind of calcium you might give them...oyster shells, eggs shells, crustacean shells, limestone, etc. They will eat it if they need it. Some say they get calcium also from the exoskeleton of some insects.

I suppose there were some chickens of yore that lived on the coast somewhere that had access to shell fish such as oysters.

X 2 - it is similar, imo, to how you crave certain things when your body is telling you that you need x, y or z nutrient.

 

[Julia62]

Once I put my two oyster shell feeders out, I was surprised how they just went to it! It's almost the first thing they go to as soon as they get out of the coop.