Border Collies demonstrate the art of herding ducks during a British dog show. Dogs are probably much cleverer than most people think, according to a new study.

Scientists are convinced that dogs can count and

researchers at the University of California Davis say they try to convey
different messages through the pitch and pace of their barks.

"Animal behaviorists used to think their bark was simply a way
of getting attention. Now a new study suggests that individual dogs have
specific barks with a range of meanings," New Scientist magazine
said on Wednesday.

Dogs usually use high-pitched single barks when they are separated
from their owners and a lower, harsher superbark when strangers approach
or the doorbell rings, according to Sophia Yin, an animal behaviorist at
the university.

Playful woofs are high-pitched and unevenly spaced.

Dogs also know when they are being short-changed on treats because
they have a basic mathematical ability which enables them to tell when
one pile of objects is bigger than another.

"But to count, an animal has to recognize that each object in a
set corresponds to a single number and that the last number in a
sequence represents the total number of objects," New Scientist
added.