Rodent
Biology & Control
Examples of Rodents
Gerbils
Mice
Rats
Squirrels
Woodchucks
Porcupines
Beaver
and….
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Objective
‫هدف‬
Relate the biology of rodents to appropriate
control measures.
Prevent Disease, Disability and Premature Death
Overview
‫مرور‬
Chacteristics and Habits
Purpose
Surveillance and Control
Techniques
Prevent Disease, Disability and Premature Death
Norway Rat
Rattus norvegicus
Characteristics:
Large, thick body
Largest, most
aggressive
Blunt muzzle; small
ears and eyes
Tail is nearly naked;
shorter than combined
length of head and
body
Fur color brown to dark
gray with scattered
black hairs
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Roof Rat
Rattus rattus
Characteristics:
Relatively slender
body
Muzzle pointed;
ears and eyes large
Tail longer than
combined length of
head and body;
fairly hairy
Fur color black to
brownish-gray
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House Mouse
Mus musculus
Characteristics:
Body small
Ears and eyes large
Fur color grayish-brown with light below
Can be distinguished from immature rats by head and feet
proportion in relation to body (young rats have large
heads and feet)
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Reproduction
Rats
Sexually mature at 3 months
Gestation period 21 days; new estrus cycle begins 4-5
days following litter birth
Produce 3-7 litters per year with 5-7 pups per litter
Mice
Sexually mature at 5 weeks
Produce up to 8 litters per year at 5-6 pups each
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Rodent Behaviors
They are nocturnal -- active almost exclusively at night.
They stay close to food and water.
If abundant water is not available (or in poor supply),
they will not continuously inhabit an area.
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Rodent Behaviors
They travel in defined runways.
They are “neophobic” -- don’t like new objects.
They tend to eat in their harborages.
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Rodent Behaviors
Climbing – Rodents are among the most agile of all
mammals and are capable climbers
Burrowing – this activity is demonstrated by all
commensal rodents with the Norway rat being most
adept.
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Rodent Senses & Abilities
Sensory acuity - hearing, taste and smell, are much more
acute than humans.
Rodents have excellent memories and seldom repeat
mistakes.
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Senses and Abilities
Swimming – all commensal rodents are good
swimmers with the Norway rat being the most adept
at this activity.
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Medical Importance
Native rodents may contribute to disease (ex.
plague and Hantavirus) or economic loss (ex.
crop damage).
Imported species are far more destructive.
We are most concerned with commensal
rodents: those rodents that are closely
associated with man and his environment
(derived from the Latin word for "companion at
meals.”)
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Medical Importance
Rodents can attack people, especially when
their populations are large or they are hungry
Rodents historically have been a problem on
battlefields and will attack wounded and
disabled soldiers
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Diseases Associated
with Rodents
Plague
Tularemia
Leptospirosis
Salmonellosis
Relapsing fever
Leishmaniasis
Korean hemorrhagic fever
Ratbite fever
Hantavirus
Mosquito- and tick-borne
encephalitides
Chikungunya, Onyongyong
fever, Lassa fever
Crimean-Congo hemorrhagic
fever
Murine and scrub typhus
Tickborne typhus, Q fever
Toxoplasmosis
Helminthic disease (trichinosis)
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Rodent Attacks
Rats can injure, maim, and kill people!
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Economic Significance
Destroy stored grains, and other foods
They will eat almost anything
Destroy other structures by gnawing
Includes electrical wires, hydraulic hoses, wood, and
wallboard
Gnawing - rodents gnaw constantly to wear
down teeth
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Surveillance
Presence of urine and feces...
Rat urine glows under black light
Smudge marks or rubs
Runs or tracks
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Surveillance
Gnawing or other physical damage
Burrows, nests, or food caches
Presence of dead rodents in the open.
Presence of live rodents in the day.
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Surveillance
Odors and sounds
Visual observation
Pet excitement
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Prevention and Control
Sanitation
IPM
Exclusion and
rodent proofing
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Rodenticides
Acute (Single-Dose) Rodenticides :
Capable of killing in a single dose, although
more effective over multiple feedings
Chronic (Multiple-Dose) Rodenticides:
Requires multiple feeding over several days
to cause mortality
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Other Control Methods
Trapping
Snap traps
Live traps
Sticky traps
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Summary
Chacteristics and Habits
Purpose
Surveillance and Control
Techniques
Prevent Disease, Disability and Premature Death
Questions?
‫سواالت‬
Prevent Disease, Disability and Premature Death