overcome. Nonfatal doses of single-dose poisons that are painful are largely overcome.
Nonfatal doses of single-dose poisons are painful, where as anticoagulants apparently
cause no pain.
c. Nonstandard Rodenticides.
(1) Zinc phosphide is a poison, which is effective against Norway rats, roof
rats, and house mice. It kills them by causing heart paralysis and gastrointestinal and
liver damage. The offensive odor and unattractive color of zinc phosphide serve as
safety factors, in that most well-fed domestic animals will not touch baits prepared with
it. However, domestic rodents seem to like the taste and pungent odor of the
phosphorus.
(2) Epibloc (alpha-chlorohydrin). Epibloc is a new rodenticide, a toxicant
sterilant. It both kills rats when lethal doses are eaten and sterilizes adult male rats,
which eat sublethal doses. Like all pesticides, epibloc must be used in strict adherence
with label directions.
d. Preparation of Baits.
(1) Rodenticides should be mixed with non-decomposing bait materials
according to the printed instructions on the label of the container. Solid and liquid baits
lose their attractiveness or evaporate after exposure and must be checked frequently to
ensure that the available supply remains attractive and plentiful and to determine if they
are located in the right places. Mix bait only as directed. Using too much poison may
give the bait a strong taste or odor; using too little will not kill and may result in "bait
shyness." Excessive amounts of poison increase the danger to man and to domestic
animals. A vomiting agent, usually tartar emetic, is mixed with zinc phosphide to protect
other animals, even though acceptability of such baits is thereby reduced. Bats are
among the few animals that are unable to vomit.
(2) Since the foods preferred by rodents vary with the species and the
geographical locality, samples should be placed for one or two nights in places
frequented by the animals to ascertain which food is accepted most readily. Test
samples should be selected from the three classes of food and fruits and vegetables
(melons, sweet potatoes, bananas). Because some rats take peanut butter readily, but
refuse bacon, for instance, several materials of each class should be tried. A binder of
molasses or of vegetable, mineral, or fish oil is often used in cereal or dry baits to hold
poison and dry bait together, and to aid in mixing
(3) Anticoagulant water baits are made by mixing sodium or calcium salts of
the coagulants in water. They are usually dispensed in bait stations similar to chicken
watering fountains. These fountains are often used in dry attics, in warehouses in which
all water sources can be restricted, and in some bait stations with adequate space for
both liquid and dry baits. Adding sugar to water baits can attract more rodents.
MD0172
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