(redirected from Rat flea)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.


name applied to various stout-bodied rodentsrodent,
member of the mammalian order Rodentia, characterized by front teeth adapted for gnawing and cheek teeth adapted for chewing. The Rodentia is by far the largest mammalian order; nearly half of all mammal species are rodents.
..... Click the link for more information.
, usually having a pointed muzzle, long slender tail, and dexterous forepaws. It refers particularly to the two species of house rat, Rattus norvegicus, the brown, or Norway, rat and R. rattus, the black, roof, or Alexandrine, rat. Both species originated in Asia, but have spread throughout the world, mostly on board ships. The black rat was common in Europe in the Middle Ages and has been historically implicated in the spreading of plague, but recent research has suggested that the great gerbil or another rodent of Central Asia may have been the source. The black rat has since been largely displaced in cooler regions by the brown rat, which reached Europe early in the 18th cent. and North America by 1775.

The brown rat is the larger of the two, growing up to 10 in. (25 cm) long excluding the naked, scaley tail and sometimes weighing more than a pound (.5 kg). It is commonly brown with whitish underparts and pink ears, feet, and tail. It is a poor climber, but an excellent burrower and swimmer; it is found in the damp basements and sewers of most temperate zone cities. The laboratory white rat is an albino strain of the brown rat.

The black rat is commonly dark gray. It reaches a maximum length of 8 in. (20 cm) and has a longer tail and larger ears than the brown rat. A good climber, the black rat inhabits attics and upper floors in warm areas; it is the common rat of the Mediterranean region, the SE United States, and Central and South America.

Rats are omnivorous, aggressive, intelligent, adaptable, and extremely fecund. Females produce as many as 8 litters each year with as many as 20 young per litter. The gestation period is three weeks, and the young reach sexual maturity in about two months. Rats may live as long as four years. They are social animals but sometimes fight among themselves.

Rats live mostly in and around human settlements, where they have few natural enemies and an abundant source of food. They invade food supplies and cause widespread destruction; they also spread human diseases such as typhus and tularemia. Despite human efforts to exterminate rats, the house rat population is probably equal to the human population.

Besides the house rats, the genus Rattus contains several hundred wild-living species. In addition, many other members of several different rodent families are called rats, e.g., the bandicoot ratbandicoot rat,
giant rat of southern Asia, unrelated to true bandicoots. It is an agricultural pest in the grain crops and gardens of India and Sri Lanka and is known for the piglike grunts it emits when attacked.
..... Click the link for more information.
, the wood rat, or pack ratpack rat,
rodent of the genus Neotoma, of North and Central America, noted for its habit of collecting bright, shiny objects and leaving other objects, such as nuts or pebbles, in their place; also called trade rat or wood rat.
..... Click the link for more information.
, the rice rat, the muskratmuskrat,
North American aquatic rodent. The common muskrats, species of the genus Ondatra, are sometimes called by their Native American name, musquash. They are found in marshes, quiet streams, and ponds through most of North America N of Mexico, but are absent from the
..... Click the link for more information.
, and the kangarookangaroo,
name for a variety of hopping marsupials, or pouched mammals, of the family Macropodidae, found in Australia, Tasmania, and New Guinea. The term is applied especially to the large kangaroos of the genus Macropus.
..... Click the link for more information.
 rat. House rats are classified in the phylum ChordataChordata
, phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals.
..... Click the link for more information.
, subphylum Vertebrata, class Mammalia, order Rodentia, family Muridae.

See also mousemouse,
name applied to numerous species of small rodents, often having soft gray or brown fur, long hairless tails, and large ears. The chief distinction between these animals and the variety of rodents called rats is in size: mice are usually smaller.
..... Click the link for more information.


See H. Zinsser, Rats, Lice and History (1935); S. A. Barnett, The Rat, a Study in Behavior (1963).


(religion, spiritualism, and occult)

The Rat is one of the 12 animals of the Chinese zodiac. It refers to one of the 12 earthly branches, which are used in Chinese astrology, together with the 10 heavenly stems. Such a branch designates one day every 12 days: the days are named according to a sexagesimal (60) cycle, made of 10 series of 12 branches.

A Rat is jovial (perhaps too much), pleasant, and sociable; with a sense of justice, the Rat tends to want to convince others. On the negative side, he is suspicious, crafty, and may hold grudges if people are disrespectful to him. With a keen interest in everything, he is hardworking, ambitious, and conscientious. He loves money: he knows how to win it, and above all, he knows how to keep it, even if he is generous with those close to him. Easy to get along with, he is persuasive and a successful businessman. Not really faithful, he is nevertheless eager for tenderness.

—Michele Delemme

What does it mean when you dream about a rat?

Rats are often associated with the decaying conditions of poverty (“rat trap”) or illness. To betray someone is to “rat” on them. Dreams of rats can also indicate a need to take some time out from the “rat race.” (See also Mouse, Rodent).


(vertebrate zoology)
The name applied to over 650 species of mammals in several families of the order Rodentia; they differ from mice in being larger and in having teeth modified for gnawing.




any of numerous long-tailed murine rodents, esp of the genus Rattus, that are similar to but larger than mice and are now distributed all over the world


(1) (Radio Access Technology) See Multi RAT.

(2) (Remote Access Trojan) Software in a user's machine that is interactively controlled by an attacker. Having full administrator rights, the attacker can perform any operation in the computer remotely and direct the RAT in the infected machine just like a user with a Web browser requests data from a server. The Cult of the Dead hackers created the classic RAT (see Back Orifice). See Trojan.


They are unpleasant and symbolize danger, poverty, filth, and illness. Your unconscious mind may be bringing up unpleasant images due to a disturbance in daily life. The dream’s purpose is to make you aware of negative feelings that may encourage you to directly deal with the negativity in your life. Dreaming about rats leaves the dreamer feeling apprehensive and disgusted. Attempt to connect these feelings with those things that produce this type of anxiety during the day.
References in periodicals archive ?
rat fleas, Xenopsylla cheopis) block more readily than others.
The respective influences of temperature and moisture upon the survival of the rat flea (Xenopsylla cheopis) away from its host.
In Mahajanga, ongoing studies have shown that the Asiatic shrew, Suncus murinus, accounts for up to 75% of the trapped animals and is a regular carrier of the rat flea, X.
Creepy crawlers discussed include African bat bugs, stinging caterpillars, Brazilian wandering spiders, oriental rat fleas and the death-watch beetles.
Bubonic plague, which is spread by bites from infected rat fleas, killed a third of Europe's population in the 14th century but can now be treated with antibiotics.
The following morning, feeling feverish and unwell, she went to a doctor in Pwllheli who told her that she had infected insect bites, probably from rat fleas.
pestis isolates obtained from the same wood rat fleas collected on the couple's property in July and November.
The late 19th-century discovery that the disease is caused by a bacillus carried by rat fleas, coupled with the use of antibiotics from the 1940s to fight the infection, have encouraged a that plague is now a toothless longer to be feared.
We must take this tiny insect seriously for although rat fleas prefer rats, cat fleas prefer a feline host, and dog fleas certainly prefer canine quarters, fleas will attach themselves to any available mammal if their hunger or thirst is strong enough.
The bubonic plague that is still found in this day and age in India and the Southwestern United States is carried by rat fleas, while ticks carrying Lyme disease can also be found on rats, albeit more in the suburban areas of the metropolitan area than in the concrete jungle.