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12. CHAPTER. Rats. Introduction to Rats. Belong to rodents order of gnawing mammals (Rodentia) With mice compose subfamily Murinae True rats form genus Rattus (78 to 570 species) Two domesticated rat species Black Brown. History of Black and Brown Rats. Black rat
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12 CHAPTER Rats
Introduction to Rats • Belong to rodents order of gnawing mammals (Rodentia) • With mice compose subfamily Murinae • True rats form genus Rattus (78 to 570 species) • Two domesticated rat species • Black • Brown
History of Black and Brown Rats • Black rat • May have come from Southern Asia • Well established in Europe during 1200s • Reached North America during 1500s • Brown rat • Came from Eastern Asia and Northern China • Went to Europe and North America in 1500s • Now well established in United States
Common Background of Rats • Have spread across the world • Can adapt to many different habitats, environments, and foods • Reproduce rapidly • Cause tremendous damage • Destroy eggs, fruits, stored grain, and vegetables • Attack humans and other animals • Damage buildings and cause fires • Carry diseases • Play important role in research • Used extensively in drug development • Act as subjects in disease, aging, behavioral, and other studies
Black Color Group of Rats • From 7 to 8 inches long (head and body) • Tail longer than head and body • Ears about half as long as head • Weigh 4 to 12 ounces • Usually black or dark gray with brown or gray-white underside • Excellent climbers and jumpers
Brown Color Group of Rats • From 7 to 10 inches long (head and body) • Tail shorter than head and body • Overall thicker, more robust than black rats • Weighs 7 to 17 ounces • Dark to gray-brown back with lighter brown or gray underside • Not climbers, prefer tunnels, burrows, sewers, and basements
Varied Color Group of Rats • Albino (white laboratory rat) • Cream, fawn, or light gray • Hooded • Caped
Characteristics of Common Rats • Agile climbers • Excellent swimmers • Highly curious • Clean and odor free • Seldom prone to biting • Imposing when upset or angry • Gregarious • Primarily nocturnal
Desired Qualities of Rat Cages • Larger than 12” x 24” x 12” • Wire mesh or glass sides • Solid bottom or pull-out tray • Outside-hanging water bottle (spout inside) • Glass or ceramic feed bowls • Exercise equipment (ladders, ropes, wheels) • Wood shavings or other appropriate bedding • Nesting materials
Methods of Feeding Rats • Commercial pellets easiest option • Supplements • Dry dog food, crackers, cereal, fruits or vegetables (less than 10% of diet) • Vitamins and minerals • Daily water • One ounce per rat • Closed dish
Methods of Handling Rats • Young rats • Grasp around body, just behind front legs • By tail, grasp at base close to body • Older rats • Use talking as relaxation technique • When not tame: Go slowly, get attention, grasp by base of tail, and lift • For further restraint: Place second hand around body just behind front legs and restrict head movement with thumb and forefinger
Rat Diseases and Ailments • Respiratory disease • Commonly caused by Mycoplasma pulmonis • Treatment with antibiotics • Controlled with good sanitation and ventilation • External parasites (lice and mites) • Cause hair loss, itching, more serious symptoms • Controlled with shampoo containing pyrethrin
Rat Reproduction • Sexual maturity at 6 weeks • Breeding should be done at 16 weeks • Gestation period from 21 to 24 days • Young born pink, naked, blind, deaf, completely helpless • Up to 16 young in a litter