Characteristics: The average weight for female rats is between 8 to 11 ounces and 10 to 18 ounces in males. Male rats mature slowly and may not be fully-grown until 2 years of age. The average life expectancy of rats range from 26 to 48 months.

Appearance: Through selective breeding, these domesticated animals come in a wide variety of colors and coat types. Exotic "fancy" rats exhibit colors such as Blue, Champagne, Lilac, Mink, Cinnamon, and Siamese in straight, curly or stain coat types.

#1 Preventable Health Problem: Improper diet is the leading cause of some of the most common ailments. A poor diet can result in obesity, diarrhea, overgrown teeth, and weakened immune system, making them susceptible to respiratory infections.

Preferences: Pet rats are very intelligent and social animals that love lots of activity and stimulation. Spend at least one half-hour a day playing and interacting with your pet outside of the cage.

Best Features: Pet rats learn to respond to their name and can be trained to come when called. They are one of the most intelligent and trainable small pets.

Housing: A wire cage with at least 12 x 24 inches of floor space is ideal for two rats. Since they love to climb, tall cages are best. Rats need and enjoy a lot of exercise, so be sure the cage is large enough to accommodate toys, exercise wheels and other accessories.

Diet: Rats require a high fiber, low fat diet. Always limit the intake of high-fat foods such as nuts and seeds and offer balanced "block" type diets. They are nutritionally complete and provide the added benefit of gnawing exercise. Add limited quantities of fresh vegetables such as dark green leafy vegetables, broccoli, and carrots.