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.
Hample and Maisy are Sprague Dawley female rats, an albino breed of rats that are commonly used in research laboratories. Sprague Dawley rats were first bred by the Sprague Dawley farm in Madison, Wisconsin in 1925 through multiple crosses with a single-hooded male and six albino female rats. The rats average about 5 grams of food per day per 100 grams of body weight and about 10-12 milliliters of water per 100 grams of body weight. The typical litter size of this rat is 10.5 and their average weight is 250-300 grams for females. The average life expectancy is between 2.5 and 3.5 years. Their respiratory rate is between 75 and 115 breaths per minute. Rats can breed between the ages of 65 and 100 days in both sexes. The rats are known for their tame disposition ...