Internal laying? ):

[Kneedles]

Twice recently, I have seen one of my hens (five-year-old black sex link) go into her nesting place for a while (which always resulted in her producing an egg in the past), but have found nothing there afterwards. Does this mean that she has become an internal layer? I have yet to see any external signs of illness, but I am keeping a close eye on her. She gets plenty of calcium in her diet and she is definitely not broody.

 

[Eggcessive]

It could be that she is laying internally. Or she could be a false layer. Here is some reading:
https://www.merckvetmanual.com/poultry/disorders-of-the-reproductive-system/false-layer-poultry

https://www.merckvetmanual.com/poultry/disorders-of-the-reproductive-system/internal-layer-poultry

 

[Kneedles]

Should I try to investigate her cloaca? If so, is there anything important that I need to know about inserting fingers?

 

[Eggcessive]

You can try checking her for egg binding by inserting a finger one inch into her vent to feel for an egg. But I had a hen who did the same thing for a long time. She was rehomed eventually.