Pictured above is an African grey parrot, its photo taken by an AP photographer. If you think it is staring at you in disapproval, that's probably not the case; while the bird's glare isn't reflective of its mood. Parrots and other birds have emotions, sure, but they aren't as complicated or as deep as humans; they almost certainly do not know how to communicate their disgust by simply staring us down. Similarly, while parrots are able to repeat the sounds they hear -- they parrot words -- they don't truly understand what they're saying.

But they do appreciate it when humans react to their nonsense. And in one case a few years ago, that proved to be a problem for a UK zoo.

The parrot above is one of five who, as recently as September 2020, lived at Lincolnshire Wildlife Park in the UK county of, you guessed it, Lincolnshire. At first, the quintet of grey parrots -- Billy, Eric, Tyson, Jade, and Elsie -- were housed together with the 200 other grey parrots who lived in the park, as you'd expect a zoo to do. But these five weren't like the others. Billy, Eric, Tyson, Jade, and Elise had picked up a bad habit at their previous home; as the Associated Press reported, the birds had a "penchant for blue language" and, per CBS News, "wouldn't stop swearing at visitors." 

Parrots, while talkative in private, tend to "clam up outside," the zoo's chief executive, Steve Nichols, told the AP. The zoo knew that the birds used foul language, but expected them to quiet down out and about. Unfortunately, that didn't prove to be the case. Here and there, one of the five would drop a choice word, which was enough to start a problem. Being parrots, they probably didn't know what they were saying -- but they did know that whatever they were doing, it was getting a reaction from the gathered guests. And that reaction fueled more curses. Nichols explained the situation to the BBC:

The parrots "swear to trigger reaction or a response" so if people look shocked or laugh, it just encourages them to do it more, he said.

"With the five, one would swear and another would laugh and that would carry on," he said.