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.
Mice never travel alone. If you find one, chances are high that your home infested. Female mice start having babies as young as two months, and they have anywhere from 30 to 100 babies per year.Even if the mice have only been in your home for a couple weeks, theyâve probably already had the first set of babies.f you find one, chances are high that your home infested. Female mice start having babies as young as two months, and they have anywhere from 30 to 100 babies per year.