I get those every so often. Mine are my chickens pecking at it. It looks the same as yours. You want to make sure you get them right away because if they start tasting the inside they will begin to eat the whole egg.
Do you have enough nesting material(straw or shavings) in the nests? Are your nests out of the way of normal chicken traffic?
I use to get quite a few eggs like that from my Dorking hens while they were in quarantine. The quarantine pen didn't have good nests with lots of cushion, so the hens were accidentally stepping on their eggs.
Make sure your nests have a lot of bedding, more cushioned the better. Also make sure your hens have access to oyster shell, that way the egg shells are harder.
Thanks everyone, thats what I thought because everything has been fine for over 2 months and now this is the second one. I notice it if they lay and get cold before I get up..... darn now I have to get up earlier or have a talk with the girls...LOL :0)