Do you know what birds use to build their nests? You may say that birds usually build their nests with sticks, leaves or grass. But do you know that birds are also building their nests with rubbish these years? The rubbish includes cigarette butts (烟头) and plastic bags.

A group of European scientists looked into about 35,000 studies on bird nests.

They found that birds have used man-made things in nests almost everywhere on Earth except Antarctica.

Some rubbish seems to be helpful. This is why birds “like” putting it in their nests. For example, cigarette butts have special smell, so they can keep insects away and protect the baby birds. Plastic bags are useful in keeping the animals warm, and other hard things, such as paper cards, can make nests stronger.

However, in the end, human rubbish may only bring more harm to birds. The toxic (有毒的) chemicals in cigarettes hurt the baby birds. They may get sick or have shorter lives, according to a study. What’s worse, if the cigarette still burns when the bird brings it back to its home, it may set fire to the nest. Pieces of fishing net may also trap birds, and it’s impossible for them to get out by themselves. If the baby birds eat other kinds of rubbish by accident, they will also get hurt. Our bird friends in the air are feeling the bad impacts of humans polluting the environment.

Most bees are brown, hairy and 8 to 22 millimeters long. Bees live as part of a large family. Over 25 000 kinds have been found. Honey bees are more common than any other bees.

Honey bees always live in groups called hives (蜂群). Each hive has a queen drones (雄蜂) workers (工蜂). Like a human society, each bee in a hive knows its own job.

The queen is the largest bee. She doesn’t go out to work but lay eggs. Sometimes a queen can 3,000 eggs in a day.

Drones do not collect food from flowers. They are the queens husbands. When there’s not much food, queens often kick drones out of the hive.

Workers are the smallest and busiest bees. A colony (种群) can have 50,000 to 60,000 workers. They collect food for the queen and babies. They guard the hive and help keep it cool by fanning (飘动) their wings. A worker only lives for 28 to 35 days.

To collect a pound of honey, a bee may have to fly a long way. Sometimes it is equivalent to (相当于) twice around the world. Bees have to visit more than 10,000 flowers to make a pound of honey.

Facts(事实) About Giraffes

Giraffes are the world's tallest(最高的) animals with long legs and long necks.Giraffes' legs are longer than many animals'.They can run 56 kilometres an hour！Giraffes are very friendly animals，and they live on the grassland(草原) in small groups of six or seven giraffes.

Giraffes can reach the leaves on the treetops，but few other animals can reach them！Even the giraffe's tongue(舌头) is long！It's about 53 cm！A giraffe eats hundreds of kilos of leaves each week and must travel a long way to find enough(足够的) food.

Mother giraffes stand up to give birth(生产)，so their babies have to fall more than 1.5 metres to the ground！But they can stand in half an hour and run with their mothers after ten hours！