You might not be able to tell crows apart, but these birds can tell you from your best friend and even warn other crows about you if they don't like you.

Crows have been known to hold grudges for up to 16 years, and that's not all they can do.

Let's find out more.

Why are crows smart?

Crows are considered one of the smartest animals in the world.

As smart as a primate, like a gorilla or chimpanzee.

Crows have been observed creating and using tools which not many animals do.

They can follow simple logical rules and communicate with each other.

They can even mimic human speech.

Crows also have social lives.

They live in families of up to five generations.

Older siblings help care for new chicks.

In the warmer months they live in family units while raising their young.

During the rest of the year, they live in enormous groups called murders.

During the day, they separate to forage for food and then at dusk, they gather in trees to roost, sometimes by the thousands.

Crows are so socially connected they've even been observed holding funerals.

They'll join in groups and researchers think the gathered attendees are trying to figure out why their fellow crow died and what danger they might need to watch out for.

The population of crows in cities is actually growing, because these intelligent birds are willing to eat pretty much anything.

They've even been known to trick and steal from other animals to get food, including humans.

Crows also eat farm crops.

That's why farmers employ all sorts of tactics to keep them away, including, you know, scarecrows.

It's a mystery why crows are so smart.

They don't have a prefrontal cortex like humans and other primates.

Researchers think that when birds and mammals split evolutionarily, they developed different brain structures while holding on to the same capabilities.

So think of different wing shapes in insects, bats and birds, for example.

Those wings are all shaped differently, but they all fly, so crows may have held on to some brainpower while developing a different, smaller brain.

Remember, be kind to these brainy birds, because if you don't, they'll remember you and they'll tell their friends.