It happens countless times a day. A flower’s bright color and the smell of sweet nectar (花蜜) attract a bee. The bee stops by for a quick taste and small grains of pollen (the powder produced by a flower) stick to its body. The bee then travels to another flower of the same type and leaves the pollen as it has another meal. This is an example of animal pollination (授粉) — a process extremely important to plant reproduction.

It’s not only plants that depend on animal pollination — humans do, too. Worldwide, nearly a thousand plants that we grow for food, spices, clothing fibers, and medicine depend on it. If pollination suddenly stopped, we would have no apples, tomatoes, coffee, and many other goods.

This important process is carried out by more than 200,000 different animal species known as pollinators. Flies and beetles - the original pollinators - date back 130 million years to the first flowering plants. Birds, butterflies, and ants also do their part. Even nonflying mammals help out: monkeys tear open flowers with their hands, accidentally spreading pollen into the air and onto their fur.

Pollinators are therefore important, but they are also at risk. Climate change, habitat loss, and invasive predators (入侵捕食者) all threaten them. The United States, for example, has lost over 50 percent of its honeybees over the past ten years. A serious threat facing bees is colony collapse disorder, when worker bees mysteriously disappear from their colony. Scientists are still trying to identify its cause.

There is a quote attributed to Einstein that if bees ever disappeared, man would only have four years left to live. Whether that’s true or not does not really matter, says wildlife photographer Louie Schwartzberg: the key point is that there is a real danger. “The healthiest food we need to eat,” he says, “would disappear without pollinating plants. It’s pretty serious.”

How to Care for a Pet Fish

Taking care of a pet is a big responsibility, so you should make sure you learn all about your pet before bringing it home.【小题1】 That's because fish can give them a good idea of whether or not they'll be able to take care of a more complicated (复杂的) pet later on.

First, choose what types of fish. 【小题2】 They are easier to raise and give you enough experience to take care of fish and their tanks (水箱). Some kinds of fish do not get along with others, so you'll need to choose what kinds to buy.

Next, make sure you have all of the necessary supplies. Fish need a fish tank. Make sure it is big enough for the number of fish. Fish tanks need a light and some machines to keep the water clean and at a comfortable temperature.【小题3】

Now you can set up your aquarium (水族馆). Wash sand and decorations (装饰物) clean and fill the bottom of the tank with them. 【小题4】 Follow the instructions on the heater to heat up the water to the temperature your fish will need. Make sure your light is ready to go, too!

【小题5】 The pet store keeper can teach you how to make your fish get comfortable before you put them into your aquarium. Once the fish are in the tank, you have to watch them closely to make sure they don't get sick. Feed them in small amounts a few times a day. You will have to change some of the water at least once a week.

A group of clams (河蚌) recently caught people’s attention after an article was posted by China Science Communication online. Although these clams are usually regarded as nothing more than delicious food, they work to monitor the local water quality in Poland.

Gruba Kaska pumping station, which stands in the River Wisla, helps provide millions of liters of water to Warsaw, the capital of Poland. However, one particular concern for the water quality has been heavy metals, and researchers sought help from nature to solve this problem.

Clams are sensitive to pollutants in their environment as they filter (过滤) water to feed on microorganisms. They shut their shells immediately after detecting “dangerous” water.

Based on this, the researchers selected eight clams at a time and recorded the natural opening of their shells. After the clam “employees” become accustomed to the local water, they are placed in a specially designed container. With sensors stuck onto their shells, the clams are connected to a system that records how wide the shells are open. If four or more clams close their shells at the same time, an alarm will be set off and the water supply will be shut down. The result is reliable because the creatures are considering many different factors at the same time, according to ZME Science.

Animals have long been helpers for human activities. Farmers in north Queensland, Australia, have been ordering different species of dung beetles to help clean up cattle waste, according to ABC News. As the number of cattle grows, their waste increases, leading to an enormous population of flies and a worsening environment. Dung beetles, however, take the waste and bury it. This way, they help improve soil quality.

Similarly, cockroaches are used to deal with kitchen waste at several firms in China, according to a report of The Beijing News. About 300 million cockroaches are fed 15 tons of food waste on a daily basis, and they themselves are a good protein resource for livestock.