They usually feed twice at night just after dark and just before dawn. They usually stay within a 100-foot radius if food and water are available but have been known to move almost a mile a day in search of plentiful water and shelter. Adult rats eat about 1 ounce of food and 1.5 ounces of water per day. Without food, weakness begins after about 3 days, but without water, weakness begins in 1 to 2 days. When weakness begins from lack of food or water, they begin to move elsewhere.
Overpopulation also causes some rats to seek new locations.
Reproduction of Rats Rats breed at 3 to 4 months of age and probably continue until about 18 months old. Gestation is 21 to 25 days. The young are weaned at 3 weeks old, often just before the arrival of another litter. A female can breed only one day after giving birth. If fertilization does not occur, she will come into heat about every 5 days.