Sometimes it’s easy to tell if a movie isn’t meant for children. Sometimes it requires warnings: Netflix's Watership Down is violent and bleak, but it’s still centered around the lives of those small, soft, carrot-nibbling critters we call rabbits, and parents seeking a cartoon for the little ones could be caught off guard. Talking animals aren’t what most people expect in an epic drama, and even after the kids are shooed out of the room, some viewers might feel like they're watching something made for children in spite of the bloodshed.

The same could be said of the 1978 animated movie and the Richard Adams book that both are based on, but the advancement of computer animation means that there’s an element of visual realism changing the game. Other classic animal stories are likewise being remade with lifelike graphics, such as Netflix’s Mowgli: Legend of the Jungle, which draws from the same fiction series by Rudyard Kipling as Disney’s The Jungle Book did in 2016. Movies and television about animals used to rely on either traditional animation or the limited (and sometimes ethically dubious) use of animal actors, but that’s no longer the case, and it’s making a difference in the way the adaptations are approached.

It’s an evolution of media that we’ve seen before. For a long time, the best bet for superhero movies was to lean into the campy special effects by producing wholesome and simplistic light fare that appealed mostly to younger audiences. As the visuals became more convincing, the stories became more mature, and now it looks like a similar change is taking place within the genre of animal stories.

RELATED: Netflix's Watership Down Is the Darkest Animated Adaptation, Ever

So far, though, the potential to match up the lifelike style with realism in the story hasn't quite panned out. The rough, long-legged rabbits in Netflix’s Watership Down look real -- if not enough to mistake them for live-action, then at least enough to expect them to act like real rabbits. To an extent, that’s what they do; the heart of the story, as in every version, is the rabbits’ struggle for survival on both an individual level and for following generations, which is nothing but fictionalized natural law. But the latest interpretation also has them acting like humans, to the point of falling in love and forming lifelong relationships.

When humans are driving a plot, sex and violence are seen as the key to making it more mature. The inclusion of animal sex would cost any story a lot of dignity, but Watership Down seems to be trying to compensate by emphasizing the violence, and by hinting at the rabbits’ reproductive urges through a metaphor of human love. Unfortunately, chastely romantic overtures don’t make the bunnies any less cute. Is there any other solution to the target age confusion without removing the role of nature entirely?

NEXT PAGE: How Dark Can You Go With CGI Bunnies? Pretty Dark, It Turns Out

One would be to reference the source material more closely. In his novel, Adams stretched plausibility in several directions, granting the rabbits language, critical thought and their own religion, but he also included the unsettling facets of life for wild rabbits. The females liberated from a farmer's hutch are considered “breeding stock” by the males. When the first litter is born to the newly established warren on Watership Down, Chief Rabbit Hazel cautions the other rabbits not to disturb the mother, lest she gets upset and eats her young. At the very end of the tale, we’re informed that wild rabbits live for three years, though Hazel lives for “much longer.” (How much longer? Four years? Five? Still pretty tragic, in human terms.)

Kipling didn’t hold back with the darkness in his animal stories, either. Viewers who know Mowgli only from his cinematic portrayals may not have heard that in the books he reached his adulthood in the jungle, shaped by his animal mentors into a legendary figure of ruthless cunning, questionable morality and vaguely defined superpowers. He’s a fascinating character without a doubt, but not necessarily one that you want your kids to emulate, and it’s not surprising that this part of Kipling’s world hasn’t made it into any movie adaptations.

RELATED: How Netflix Shaped The Darkest Jungle Book Story, Ever

Without it, though, the juvenile vibe clings to Mowgli's onscreen portrayal, even in the pointedly dark Mowgli: Legend of the Jungle, just as it clings to the romantically inclined rabbits of Netflix’s Watership Down. Adams and Kipling may have given their animal characters voices and human intellect, but the real drama and edge in their stories came from the raw, unforgiving lives of creatures in the wild.

When all is said and done, though, that’s the same quality that causes problems with aiming for realism when writing talking animals. Some of the natural behaviors of fauna are just plain uncomfortable to consider through the lens of human morality, and without that lens, there's no story worth telling. Accepting and exploring the discomfort may be manageable in books, but the change of medium makes a difference. Universal hardships like violence and death provide the kind of drama that works in movies and television because we can see the characters as “us,” regardless of their species. Animal hardships remind us that they’re different.

For now, it looks like animal stories are finding their audiences by playing it safe and letting their characters be a little more human than not. With so many possibilities in literature and the animal kingdom, though, there may be adaptations in the future that break the pattern and use the realism of modern animation as a mirror for realism in the story.