I totally believe this. Years ago we had a white silkie that hatched 2 BB Mille Fleur d'uccle (along with some others). The two d'Uccle pullets were full grown when I went into the coop to find Sylvia (the hen) dead on the floor. One of the pullets had her head pushed under her mom's wing, while the other pullet stood over them and kept the other chickens away. We'd had other instances where birds that had died were cannibalised, but there wasn't a mark on Sylvia. Blew me away. I have two hens who were the only ones to survive a hatch and they do everything together. If they lose sight of each other the noise is quite something. They have to be able to see each other at all times.
