Science is constantly letting us know that some animals are more intelligent than we thought. For example, did you know that pigeons are capable of learning higher math, to a similar level as monkeys?
Back in the 1990s, an experiment was conducted to see if monkeys can learn operations more complicated than simple counting. The monkeys showed they can rank the items from the lowest number to the highest and were equally successful when given an unfamiliar number on the test. Once they learned that 2 was more than 1 and 3 higher than 2, they were able to conclude the relations between other numbers, too.
A scientist from New Zealand, Damian Scarf, tried to do the same with pigeons. He found that the birds can learn how to rank shapes and arrange the numbers in order.
The training was limited to one-digit numbers, but it’s still pretty impressive.