The series of bodily changes that occur in the female of most mammals from one period of estrus to another. The estrous cycle usually takes place during a specific period known as the breeding season, which ensures that the young are born at a time when the chance of survival is greatest.
ear-to-ear. It's about smiling. Ear-to-ear smile or grin is when you have a very broad and generous smile. Such a smile when each corner of your mouth is by each of your ears. Explain to me why you don't have an ear-to-ear grin right now.
1 smile in response to smile. 2  coo (or other non-cry vocalization) 3  lift head 45Âº when prone. 4  track object moved in short arc near face past midline. 5  bring hands together. 6  smile spontaneously. 7  laugh or squeal.  track object moved in arc near face from side to side.