What Do Animals Understand About Numbers?

Some experiments tell us that monkeys can count to three, but not to four. Is there some cognitive function that keeps them from counting higher? After all, monkeys have five fingers on each hand, and ten toes as well, so you'd think they could count at least as high as five. And how do scientists construct these experiments, anyway? You might be amused to find that they do it with magic tricks, because a monkey will display dismay and confusion when a number of objects does not match their expectations. However, it turns out that what we know as counting, and math as a whole, isn't the same for animals as it is for humans. Once scientists figured that out, the way monkeys and other animals calculate amounts makes perfect sense. Human are the weird ones here, and it doesn't have as much to do with our understanding of math as it has to do with our language.  -via Laughing Squid