Spring-loaded bar mousetrap

The traditional Spring-Loaded bar mousetrap is a simple device with a spring loaded bar and a trip to release it. Instead of baiting with cheese, now their are special baits such as Provoke which will ensure your mouse trap is effective.. The spring-loaded bar swings down rapidly and with great force when anything, usually a mouse or a rat, touches the trip. The design is such that the mouse's neck or spinal cord will be broken, or its ribs or skull crushed, by the force of the bar. Rats can easily escape from a mousetrap, so a larger version is used for them. Newer spring mouse traps have a plastic extended trigger made to look like a piece of Swiss cheese that is the color of American cheese. This is not intended to attract the mouse, but is to provide a larger surface area for the trigger mechanism and provides reservoirs for bait to be applied, such as peanut butter.

Some modern plastic designs have the advantages that the trap can be set by the pressure of a single finger on a tab and that a dead mouse can be removed from the trap without touching the corpse.

Jaws Mousetrap

Jaw mousetrap designs consists of a set of plastic jaws operated by a coiled spring and triggering mechanism. When a mouse ventures inside of the jaws to where the bait is held, the trigger snaps the jaws shut.

Live-catching mousetraps

Other trap designs catch mice alive so that they can be released into the wild. It is important to release the mouse promptly – as mice can die from stress or dehydration – and at some distance, as mice have a strong homing instinct. Survival after release is not guaranteed, since house mice will tend to seek out human buildings, where they might encounter lethal mousetraps or may be eaten by predators. In the wild, house mice are very poor competitors, and cannot survive away from human settlements in areas where other small mammals, such as wood mice, are present.

Mouse Characteristics

Mice range in size from 12 to 21 cm (4 to 8 inches) long (including a long tail). They weigh from .25 to 2 oz (7.1 to 57 g). The coat color ranges from white to brown to gray. Most mice have a pointed snout with long whiskers, round ears, and thin tails. Many mice scurry along the ground, but some can hop or jump.

Distribution and habitat

All species of Mus are native to Eurasia and Africa, where they range from lowlands to mountaintops. The five species in the subgenus Pyromys are found in Sri Lanka, India, Pakistan, and mainland Southeast Asia. Much of their range originally consisted of open grasslands or grassy patches in forests.

Reproduction

Breeding onset is at about 50 days of age in both females and males, although females may have their first estrus at 25-40 days. Mice are polyestrous and breed year round; ovulation is spontaneous. The duration of the estrous cycle is 4-5 days and estrus itself lasts about 12 hours, occurring in the evening. Vaginal smears are useful in timed matings to determine the stage of the estrous cycle. Mating is usually nocturnal and may be confirmed by the presence of a copulatory plug in the vagina up to 24 hours post-copulation. The presence of sperm on a vaginal smear is also a reliable indicator of mating.

Female mice housed together tend to go into anestrus and do not cycle. If exposed to a male mouse or the pheromones of a male mouse, most of the females will go into estrus in about 72 hours. This synchronization of the estrous cycle is known as the Whitten effect. The exposure of a recently bred mouse to the pheromones of a strange male mouse may prevent implantation (or pseudopregnancy), a phenomenon known as the Bruce effect.

The average gestation period is 20 days. A fertile postpartum estrus occurs 14-24 hours following parturition, and simultaneous lactation and gestation prolongs gestation 3-10 days owing to delayed implantation. The average litter size is 10-12 during optimum production, but is highly strain dependent. As a general rule, inbred mice tend to have longer gestation periods and smaller litters than outbred and hybrid mice. The young are called pups and weigh 0.5–1.5 g (0.018–0.053 oz) at birth, are hairless, and have closed eyelids and ears. Cannibalism is uncommon, but females should not be disturbed during parturition and for at least 2 days postpartum. Pups are weaned at 3 weeks of age; weaning weight is 10–12 g (0.35–0.42 oz). If the postpartum estrus is not utilized, the female resumes cycling 2-5 days postweaning.

Newborn male mice are distinguished from newborn females by noting the greater anogenital distance and larger genital papilla in the male. This is best accomplished by lifting the tails of littermates and comparing perineums.