The antechinus is a small marsupial native to Australia. There are several species of antechinus, including the agile antechinus, yellow-footed antechinus, and brown antechinus. Antechinuses are known for their unique reproductive behavior. Males have a short lifespan of only about 11 months, during which they mate intensively with multiple females. This intense mating period takes a toll on their bodies, leading to a rapid decline in health and ultimately death. This phenomenon is known as semelparity or "suicidal reproduction." During the mating season, male antechinuses experience high levels of stress due to competition for mates. They produce extremely high levels of testosterone, which suppresses their immune system and leads to physiological changes such as fur loss and weight loss. As a result, many males die shortly after mating.

Female antechinuses, on the other hand, have a longer lifespan and give birth to multiple litters of young each year. They care for their offspring until they are old enough to fend for themselves. Antechinuses are primarily insectivorous, feeding on a variety of insects, spiders, and other small invertebrates. They are nocturnal animals and spend most of their time foraging for food at night. These small marsupials are found in various habitats across Australia, including forests, woodlands, and heathlands. They are agile climbers and can often be found in trees or shrubs. Overall, the antechinus is an interesting and unique marsupial species known for its short lifespan and intense mating behavior.