The stomach has three types of contractions: There are rhythmic, 3 per minute, synchronized contractions in the lower part of the stomach, which create waves of food particles and juice which splash against a closed sphincter muscle (the pyloric sphincter) to grind the food into small particles.
7 What is the gestation period, how many babies do they have, and when are they weaned? 1  The gestation period for rats is 19â22 days, for mice it is 17â21 days.  Rats and mice average 8â12 babies in a litter, but can have as few as 1 or as many as 20.
How long does pregnancy last and how many kittens will by cat have are two of the most common questions cat owners have. The regular gestation period for cats is between 58 and 65 days, or approximately 9 weeks. A queen (pregnant cat) may have anywhere from 1 to 8 kittens at a time. The average being 2 to 5 kittens.