I have an ISA Brown who has started laying shell less eggs. She started about 2 weeks ago. She laid 5 in a row and then 2 normal eggs. Now we are back to shell less eggs. They are always laid sometime between the time they hit the roost and when they come out in the morning. The two normal eggs appear to have normal shells. I haven't noticed a difference when cracking or using the eggs. Oyster shell is out in two containers. I have checked her for mites, lice etc. She looks fine. I am waiting on some Verm X (all natural) from the UK (slow boat evidently) so that we can continue to use the eggs while deworming. The one thing I have noticed is that she is losing a few small feathers. Her appetite seems to be normal and she still enjoys freedom in the back yard. She gets a mix of 20% pellets mixed with chicken scratch (4 to 1 ratio). We are in Colorado. Low temperatures have bounced between 10 and 25 at night. Does anyone have a clue what I am dealing with?