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The roof rat is a climbing animal,as the name implies.

The roof rat prefers to live above ground

and frequently nestsunder the eaves of roofs.

Like the Norway rat,

the roof rat generallyuses established runways

in getting to and from its harborage.

The runways of the roofrat are usually above ground.

This is a typical roof rat run.

It can be identified by the greasysemicircular smudges

left by the rat's bodywhere it contacts the beams.

To the roof rat, a runway is a safe pathfollowed by other rats before.

Using such a runway givesa rat a sense of security.

The rat knows at one end must be harborage

and at the other end, food or water.

The runway often leadsthrough double walls.

The rat's vibrissae,or whiskers, and its long,

tactile hairs enable it to movesafely through narrow places.

The rat knows that the runway leads

to an established source of food supply,

as shown by its unhesitatingand direct approach to the food.

The roof rat is a pantry thiefand is fond of cereals and grains.

It is not primarily a garbagefeeder but will eat garbage

when other food is not available.

A rat must have accessto a source of water.

The need for wateris conveniently fulfilled

when dishes are leftsoaking overnight in the sink.

The roof rat is peculiarlyadapted to climbing.

It has sensitive finger-like toes,ending in talon-like nails.

The front paw has four clawsand a rudimentary thumb.

The inside of the paw is padded.

The hind paw has five toes.

Equipped with these tools,

the roof rat can easily climba three-quarter-inch pipe.

Notice the way the rear and frontpaws are held in the descent.

The Norway rat can climb too,but not nearly as well as the roof rat.

The roof rat can crawl upa three-inch pipe with ease.

The rough finish of the metalhelps it to take hold with its claws.

The Norway rat, by trial and error,

learns to brace its backagainst the wall and make the climb.

A roof rat bracing its back

against the wallcan climb a four-inch pipe.

Without the wall,even a roof rat would be unable

to climb a pipe four inches in diameter.

A brick wall can be scaledby a roof rat if the edges

of the brick protrudeeven one-sixteenth of an inch.

The Norway rat can pullitself up the same wall,

but with a little more difficulty.

A roof rathas an excellent sense of balance

and can walk on a wire with skill.

The Norway rat is more awkward

and falls off before learningto balance itself.

A roof rat can race surefootedlyalong a smooth, narrow pipe.

The Norway rat falls off.

The superior climbingability of the roof rat explains

its preference for nests in placeslike the air-vent shaft on a roof.

The wire mesh screen in the shaftsupports the roof rat's nest.

The dead space between the roofand parapet wall provides harborage.

From here,the rat has access to the interior

of the building by wayof the soil vent pipe.

In the South and Southwest United States,

the roof rat frequently nests in palm

or other trees that provideshelter in a mild climate.

They subsist partially on the fruitof the tree in which they nest.

At night, by such means as service wires,they gain access to homes.

Once in the building,

the rat picks up establishedtrailways leading to food.

The roof rat, like the Norway,lives its entire life close to man,

yet in concealment from him.

In these remarkable photographs,

actual scenes of the birthof a roof rat litter are shown.

The mother rat, with its forepawsand teeth, helps deliver its young.

The rat washes its newborn withits tongue and eats the placenta.

The rat places the newborn out of the way

and concentrateson each infant as it is born.

It cuts the cord and consumes it.

In this manner,the roof rat delivers its entire litter.

The baby rats are blind and helpless.

The mother rat almost immediatelybegins to suckle it's young.

As in the case of the Norway,

the young roof rats are suckledfor four or five weeks.

By that time, they are weanedand begin to explore their environment.

With growing independence,they widen their range of activity.

With an increased population,and when food

or harborage is scarce,vicious fighting results.

Though the living habitsof Norway and roof rats differ,

there is a basic similarityin their life patterns.

Both are fundamentally spoilers,

living on man's propertyand eating his food.

Both have physicalcharacteristics that equip them

to live undercover as parasites of man.

Both depend on their senses,particularly those of touch and smell,

to move around freely in the dark.

Both build their nestsin concealed places.

Both use established runwayslinking food and harborage.

Although their food preferences differ,

both can eat anythingthat man eats or discards.

Sometimes, there is competitionbetween the species for the same food.

In such a case, vicious fighting results.

The roof rat depends on speedand agility to escape the Norway rat,

but the Norway rat, which is strongerand more ferocious, wins.

Wherever Norway rats invade a roofrat area, the roof rats tend to leave.

Both Norway and roof ratshave many natural enemies.

Among these are owls, hawks, and snakes.

In rural areas, rat snakes will hidein barns and fields, near rat runs,

and stalk the rats.

As the rat goes by,the snake makes a pass at the rat.

The rat may defend itselfor carry the battle to the snake

but once the snake has thrown a coilaround the rat, the rat cannot escape.

The snake will crushit and consume it later.

In spite of the rat's natural enemies,it has survived and prospered.

Whichever route it is, Norway or roof rat,

it is a tenacious and adaptable animal.

To meet the threat it posesman must use his knowledge

and all the scientific resourcesat his command.

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