You’ve seen the viral videos: a cat nurturing ducklings, a dog romping with a deer — even a jaguar nuzzling a Jack Russell. So what gives with these improbable pairs?

Many researchers believe that animals experience more emotions than we ever thought possible. Sometimes those just might trump instincts, especially when youngsters are involved. When an orphaned 1-year-old hippo named Owen met a 130-year-old giant tortoise named Mzee [mih-ZAY], the two formed an instant bond. It was speculated that Mzee’s round shape resembled Owen’s mama in the fearful youngster’s eyes.

In other cases, a strong maternal instinct might kick in. Take the cat that recently gave birth to kittens and then, driven by hormones, adopted some newly hatched ducklings as well.

Whatever the reason, it looks like companionship can sometimes sooth a savage beast.