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Honeybees understand that “nothing” can be “something” that has numerical meaning, showing that they have a primitive grasp of the concept of zero, according to a newly­published study in Science.

Previous experiments have shown that honeybees have some facility for numbers, because they were able to count landmarks (µØ±ê) as they searched around for a sweet reward. But in these tests, the insects couldn't count very high—only to about four. Still, that made researchers in Australia and France want to explore what else the bees could do with numbers.

Scarlett Howard at RMIT University in Melbourne attracted bees to a wall where they were presented with two square cards. Each card had a different number of black symbols, such as dots or triangles. Howard trained one group of bees to understand that sugar water would always be located under the card with the least number of symbols. “They could come and see two circles versus (Óë……Ïà¶Ô) three circles, or four triangles versus one triangle£¬” she explains. The bees quickly learned to fly to the card with the fewest symbols.

But then they got another test. The researchers presented the bees with a card that had a single symbol and a blank card. The bees seemed to understand that “zero” was less than one, because they flew toward the blank card more often than expected if they were choosing at random. “When we showed them zero versus six, they did that at a much higher level than zero versus one£¬” Howard says. “So what that tells us is that they consider zero as an actual quantity along the number line.”

Aurore Avarguès­Weber, a researcher from the University of Toulouse, points out even very young children have trouble understanding that zero is a number. “It's easy for them to count one, two, three, four, but zero, it's not something to count£¬” she explains. What's more, the brains of bees are incredibly tiny brains compared with the brains of humans, scientist Nieder notes. Even so, the bees can understand the abstract concept of an empty set and he says he found that very surprising.

1£®What did the earlier studies find about bees?

A£®They could fly higher than expected.

B£®They could understand some numbers.

C£®They could remember a reward well.

D£®They could explore local landmarks.

2£®What did bees learn to do in Howard's first test?

A£®Distinguish circles from triangles.

B£®Draw various symbols on the cards.

C£®Identify the smaller of the two numbers.

D£®Locate sugar water with symbol shapes.

3£®Why did bees fly to the blank card more frequently?

A.They were told the location of the reward.

B£®They chose to do it thoroughly by chance.

C£®They preferred the card with nothing on it.

D£®They thought of zero as an actual number.

4£®Why are young children mentioned in the last paragraph?

A£®To argue that bees have a surprising memory.

B.To show that bees' gifts for numbers are amazing.

C.To explain that bees learn as well as young children.

D.To confirm that bees are smarter than young children.