What is a cuttlebone?

This was used by monumental masons to clean polished granite. You'd soak the cuttle bone in a bucket of water and gently rub flat side on the granite.

my budgies and lovebirds love eating it!!

I thought it was the skeleton of the cuttlefish, internal shell seemed wrong but I used the majority and thankfully a lot of people were smarter than me!

which birds love. my 2 budgies especially!

Player #29684811, Apart from a small supply to some restaurants (they are cooked like squid) cuttlefish are not targeted. They are short lived and most cuttlefish shells can be gathered from ocean beaches where they have washed up especially after storms.

would hang it in our budgies cage for calcium when I was a kid