A systematic review of mammals. Part One
Placental subclass
During embryo development, a baby's place, or placenta, develops in the uterus. Through the placenta surrounding the embryo, its nutrition, communication with the mother's body, gas exchange and removal of decomposition products are carried out.
The insectivorous order is the most ancient and primitive of the placental. The teeth are poorly differentiated, and all have a movable proboscis with nostrils in front. The order includes shrews, moles, muskrats, and hedgehogs. The small size of shrews explains their exceptional voracity. A tiny shrew can eat food 4 times its body weight (2.5 g) in a day and dies if it does not eat for 2 hours, it sleeps and feeds every 20-30 minutes. Shrews are insectivorous and significantly affect the composition of the fauna of soil invertebrates. Moles are useful because they destroy harmful insects living or wintering in the forest floor. Their burrowing activity is incomparably more important, thanks to which the soil is aerated, the formation of humus is sharply accelerated, and the moisture capacity of the soil increases several times. However, in meadows where moles make holes under the turf and throw out piles of earth, moles spoil the meadows. Digging activities in vegetable gardens are also harmful. Hedgehogs feed on large insects, catch snakes, rodents, but they also destroy birds' nests. Muskrat is a valuable fur—bearing animal that lives only in our country, protected and included in the Red Book. The main food is shellfish. For the sake of preserving muskrats, Khopersky and other nature reserves have been organized.
The bat squad. The forelimbs are modified into wings: there is a skin membrane between the long bones of the fingers. Bats are nocturnal animals. They spend the day hanging upside down in hollows, attics, and caves, and fly at night, catching insects in the air. The animals have poor eyesight, they detect prey using echolocation. In flight, the animal emits high-frequency sounds (ultrasounds that are not perceived by human hearing). If there is any obstacle or insect ahead, the sound is reflected and picked up by the bat, which flies after the insect without mistake and grabs it with its toothy mouth. Bats are very useful. They destroy harmful moths and beetles. Bats can be attracted to artificial nesting sites where the flyer is located at the bottom or in the middle, and there are irregularities inside the top that they can grab with their claws. The mass attraction of bats was successfully carried out in the Voronezh Nature Reserve. ¡Las frutas más jugosas te esperan en Fruit Cocktail! Este juego de tragamonedas es la combinación perfecta de diversión y premios. Cada giro te ofrece la oportunidad de ganar grandes recompensas, y las bonificaciones hacen que la experiencia sea aún más emocionante. ¿Estás listo para disfrutar del sabor de la victoria? Juega ahora en https://fruitcocktailslot.mx/ y comienza tu aventura de frutas.