Birds suffer the best hardship: Flying thousands of miles, not eating or drinking

Large worms can fly 4,000 miles (more than 6,000 km) at a speed of 60 mph without stopping to eat or drink water.

The worms are called wading birds, about the size of small pigeons. This species usually resides in the Eastern European summer, then migrates to winter Africa.

Worms are considered one of the most arduous animals in the animal world (Photo: Utahbird.org ).

British and Swedish researchers attached electronic devices to three male worms, tracking their flight from Europe to Africa. Results showed that one bird performed 3,834 miles in three days, another flew 4,445 miles in three and a half days, the other flew 2,871 miles in 48 hours.

By spring, they followed the same journey of these birds, and their flight speed was about 33-60 mph. During the flight, they never stopped to get food like other wading birds.

Grahame Madge, a member of the Royal Society for the Protection of Birds (RSPB), said: 'Large worms are usually large. Surprisingly, they can travel long distances without resting. Some other birds often stay fixed and regular at some point to regain energy ' .

This bird was formerly seen in England, but they were hunted a lot. Today, this bird becomes rare, usually 2-3 people are discovered each year.

Many other birds can fly at greater distances, but the speed is not as fast as the worms. For example, terns in the Arctic fly 50,000 miles a year to migrate from the Arctic to Antarctica and vice versa. But their journey lasted for several months.

Therefore, worms are considered to be one of the most difficult animals in the animal world.