Whether they’re pets, wildlife, or the residents of the local zoo, animals can sometimes seem a lot like us.

Usually, if you think your cat looks guilty, you’re just being anthropomorphic -- or finding human traits in nonhuman things. Because let’s be honest: Your cat probably doesn’t feel guilty about anything.

Still, some animals do have behaviors that seem oddly similar to the things we do. Their motives normally aren’t the same, and the behavior often isn’t as complex, but it can make some of the stuff we humans do seem almost universal. Here are six of the weirdest.

If you’ve ever been cut off by a bad driver, you know humans are great at holding grudges. But we’re not the only ones. Crows are known for being really smart, and an experiment done in Seattle in 2011 showed that they’ll also hold grudges… for years.

At five different sites, researchers put on a distinct mask, captured between seven and fifteen crows, and attached identifying bands to their legs. And after they were released, those crows remembered the “face”, or mask, of their persecutor for a long time. Anyone assigned to walk around in the mask would be subjected to loud crow scolding -- or angry cawing -- and even dive-bombing.

Talk about drawing the short straw. But according to the paper, which was published in the journal Proceedings of the Royal Society B, it wasn’t just the captured crows that were angry. Other local crows that hadn’t been captured, as well as young crows born in the following years, picked up this behavior as well, apparently learning from their flockmates or parents that the mask was dangerous.

The scolding behavior spread over a kilometer from the original capture sites and persisted for at least five years. A follow-up study using PET scans, published a year later in Proceedings of the National Academy of Sciences, showed that when captured crows saw the threatening mask, the same parts of their brains were activated that light up in human’s brains in response to fear-based learning. Still, a grudge like this probably isn’t the same as the ones we keep.

Because, honestly, we’re usually a lot pettier and not in actual danger. In crows, this behavior shows that they can alert each other to threats in their environment, which is important for avoiding predators and raising their young. Still, if you’re planning to visit Seattle, maybe avoid wearing a mask.

We warned you. All kinds of studies have shown that humans don’t do well in isolation. Loneliness increases our risk for all sorts of things, including infections and depression.

And, as it turns out, cows are better when they have friends, too. On a typical dairy farm, calves are separated from their mothers shortly after they’re born, then are housed alone for eight to ten weeks while they’re weaned. This is supposed to slow down the spread of disease between individual cattle, which can be a problem when you’ve got a lot of animals sharing limited space.

But scientists also noticed that cows raised alone tend to be more awkward and anxious when they joined a herd. So they came up with two experiments to compare calves housed alone with those raised in pairs, and their results were published in 2014 in PLOS ONE. In the first experiment, eighteen baby cows were confronted with a Y-shaped maze with a white box in one arm and a black box in the other.

The scientists taught the calves to expect full bottles of milk in only one color box, then switched it around to see how long it would take for them to catch on. And the calves that were raised with a buddy were quicker to figure it out than the loners. In the second experiment, researchers showed those calves a red plastic bin eight times over a couple of days, letting them interact with it for up to five minutes.

The calves raised in pairs got bored with it pretty quickly, and spent less time interacting with it each time -- because, well, it’s just a bin. But the calves that were raised alone kept coming back to check it out again and again. Put these two tests together, and they suggest that the calves raised in pairs were more flexible and probably less anxious, able to adjust to changes in their environment faster.

In other words, cows need friends, too. Meanwhile, African wild dogs have lots of friends. They’re among the world’s most social canine species, and they live in packs led by a dominant breeding pair.

Before the pack heads out on a group hunt, they need to reach an agreement about their course of action. To do this, they take a vote… by sneezing. Thankfully for our immune systems, we humans have ballots.

Scientists discovered this behavior by observing rallies, or big group interactions the dogs have before a hunt. They followed five different packs -- about 50 total dogs -- for almost a year, and published their results in Proceedings of the Royal Society B in September. They noticed that during rallies, individual dogs make noises that sound a lot like a sneeze -- although they’re not actual sneezes, just a fast, exhale through their nose, like a huff.

After analyzing almost 70 recordings of these pre-hunt rallies, scientists found that the more sneezing was going on, the more likely it was that the pack would hunt. In other words, it seemed like the sneezing was a kind of voting mechanism. Now, voting isn’t actually unique to African wild dogs -- other social species, including meerkats and capuchin monkeys, have their own ways of reaching agreements.

But remember how each pack is ruled by a couple of dominant dogs? If the pre-hunt rally was initiated by one of these power players, it took about 10 fewer sneezes on average for the pack to come to agreement and move out -- even though the dominant dog could still be overruled with enough votes. Just like in human elections, some individuals ultimately have more sway than others.

But when African wild dogs start running campaigns, we’ll let you know. If you get a bunch of people together, there’s a good chance someone will start gossiping. And, based on research, we think dolphins do, too.

Individual bottlenose dolphins have identifying whistles that act a lot like names. They’ll respond to recordings of their own so-called “signature whistles,” and they use them to call out to each other when restrained. Except, unlike humans, dolphins don’t assign these whistles to their babies when they’re born.

Dolphins develop their own when they’re a few months old, and they can also be used to convey their mood, not just their identity. They don’t often use the whistles within their own groups, but they do exchange them when meeting other groups -- like a proper introduction. But sometimes, the signature whistles they’re using aren’t their own: They’re whistles that refer to other dolphins that aren’t around.

Scientists are still figuring out why, but it seems that they’re talking about these individuals behind their backs -- or behind their dorsal fins. But because we don’t totally understand how they work, it’s probably not identical to human gossiping. Instead, they might just be trying to figure out where their missing buddies are.

Still, all that complex social behavior may have started the same way it did in humans: with large brains. A study published in Nature Ecology & Evolution in October looked at behaviors in 90 species of whale and dolphin, and found that those with larger brains have more complex social lives. This fits with something called the cultural brain hypothesis -- the idea that our big brains evolved to help us deal with living in social groups.

And now, that may apply to dolphins as well. So, gossiping may actually be a sign of advanced intelligence… but don’t tell your busybody neighbor. If you’ve ever been told you see the glass half empty, you can probably relate to honeybees.

Research published in the journal Current Biology in 2011 showed that when things get stressful, bees become pessimists -- like you on a Monday. To test this, scientists trained bees to associate different mixtures of two smelly chemicals, hexanol and octanone -- which are carbon chains with an atom of oxygen -- with different foods. Mixture one was mostly hexanol with a little bit of octanone, and was paired with delicious, sugary foods.

Mixture two, which was paired with bitter-tasting quinine, had the ratio flipped, with more octanone than hexanol. The bees quickly picked up on this and rejected the bitter food that smelled like the second mixture. Then, to change the bees’ mood, the scientists, well, shook it up a bit.

They took half of the bees and gave them a hard shake on a vortexer, a machine used to mix chemicals, which simulated a predator attacking their hive. Afterwards, those stressed-out bees had noticeably different reactions to the food. Both groups were eager to check out the snack that smelled more like hexanol, since they’d been trained to associate it with sugar.

But the shaken bees were more hesitant overall. The biggest difference was when the bees were given food scented with a fifty-fifty mixture of the chemicals -- a mix that could have been delicious or bitter. The stress-free, unshaken bees went for it like optimists.

But the shaken bees seemed more pessimistic and stayed back, since there was a chance it would be disgusting. Scientists think the stress could have affected the bees’ brain circuits that encode their memories of smell, based on the drop they saw in certain neurotransmitters. Similar tests on humans, monkeys, dogs, and birds show that we all become more pessimistic after a stressful experience.

And it’s especially cool that this also happens in invertebrates, like bees. Still, since bees lack an equivalent of many of our basic brain structures, we can’t really know if this means they experience emotions in a way we’d find familiar. But scientists think it’s a possibility worth considering.

And finally, penguins… They aren’t as innocent as you think. Adélie Penguins build their nests out of hundreds of stones, creating a platform that can keep their eggs safe from floodwater in the spring. They treat these rocks as valuable objects, fighting over them and stealing them from each other’s nests -- but sometimes, they’ll go even further than that.

These penguins are socially monogamous, meaning they pair off with one partner to raise their young… but they’re not necessarily sexually monogamous. Paired-off female penguins will often head out to collect stones to build their nests. And according to research from the journal The Auk in 1998, these wandering ladies have been observed soliciting sex from single males in exchange for rocks.

These females aren’t changing their mind about their mate, either -- they’re just offering a one-time hook-up for stones. In other words, they’re doing something that looks remarkably like prostitution. Occasionally, these females even initiate a courtship ritual... but then leave with a stone without actually copulating.

One female penguin just kept doing this and, by going back and forth, gathered at least 62 stones from a single male in an hour. Now, according to the study’s author, only a few percent of female Adélie Penguins actually do this. And even though the rocks are a useful prize, there may be more going on, too.

It takes hundreds of rocks to build a nest, and the lady penguins usually only get one or two from the single males. So there’s also a chance they’re looking for potential mates in case theirs dies, or are trying to make sure their offspring are extra healthy. Either way, this is the only animal species we’ve seen where individuals trade sex for anything other than food.

And all those cute penguins in documentaries… are maybe not as child-friendly as they seem. Whether it’s lonely cows or busybody dolphins, many animals have lives that seem a lot like ours -- even if most human behaviors are still more complex, or happen for different reasons. But the next time you’re feeling pessimistic or having a hard time with a grudge, at least you’ll know you’re not alone.

Thanks for watching this episode of SciShow! If you’d like to learn even more weird animal facts -- or stories about a bunch of other weird stuff -- you can go to youtube.com/scishow and subscribe.