Chicken embryos can be "woken up" in the egg long before hatching by rousing them with the sound of clucking hens, a study has found.
Other noises have no effect - only the clucking of a hen, the Daily Mail reported Friday. The findings may have important implications for premature babies, researchers believe.
"This work showed that embryo brains can function in a waking-like manner earlier than previously thought - well before birth," said study leader Evan Balaban, from McGill University in Montreal, Canada.
The researchers found that during the final stages before hatching, the chicks displayed brain activity that mirrored being asleep or awake, the newspaper added.