The functions of the brain in earthworms are performed by the periaesophageal ganglion, which in ringworms is divided into supraesophageal and subesophageal ganglia. These ganglia are interconnected and form the periaesophageal ring.
About half of the pandas born are twins. Of the twins born, usually only one survives to adulthood, as the mother usually chooses the stronger young to feed while the other dies of starvation.
Because of the mother's inability to store fat, her body is unable to produce enough milk to feed all of her babies. One to three young may be born during a single pregnancy.
