As any parent knows, it's hard enough to get kids to go to sleep on a good night. Add digital distraction to the nighttime mix and you may be in for a battle of wills. But, while several studies have found that media consumption can lead to sleep trouble for kids, it was never made clear whether the issue was watching TV or the content in specific shows.

Now, in a new study, researchers pinpoint "violent" kids programming that is particularly detrimental to childrens' sleep patterns.

To reach their conclusions, a team at the Seattle Children’s Research Institute looked at the sleep and TV-watching habits of 565 kids ages 3-5 . The families who participated answered questionnaires about their kids’ sleep habits and then completed the same survey 6 months into the study, 12 and 18 months. The researchers split the families into two groups. “One group received a home visit, follow-up phone calls and mailings with coaching about how to make better media choices for their young children,” HealthDay reports. The other group, the control group, only received nutrition mailings.

Prior to the intervention, researchers documented no significant difference of sleep and TV habits between kids in the focus group and children in the control group kids. But after, kids of parents who swapped “violent” programming for more age-appropriate shows had substantially less trouble falling and staying asleep each night.

They found that kids who only viewed programming that was considered “age-appropriate” were 64 percent less likely to have sleep problems that include “trouble falling asleep, difficulty staying asleep or nightmares,” HealthDay reports. What’s tricky about the findings, lead author Michelle Garrison says, is that parents have trouble identifying what shows could be considered violent to a young child.

She identifies Scooby-Doo and SpongeBob SquarePants as shows that may be too violent for a 3 or 4-year-old without parents realizing it. Last fall, SpongeBob got a bad rap when researchers suggested the show's quick animation sequences cause attention problems among toddlers, but they hadn't looked at the effects he had on sleep.

"The fact that Bugs Bunny can be too violent for a 3-year-old is not something that always clicks with some families," Garrison told USA Today. "Yes, they may know that (a preschooler) shouldn't watch the latest Transformers movie, but they may not necessarily make that same association with cartoons that have the more funny violence or the superhero violence, because some of the content is marketed toward preschool-age children."

According to USA Today, the shows this study classifies as safer for little kids to watch at night are Sesame Street, Dora the Explorer and Curious. Another plus side: "These shows can be beneficial for preschool children to watch, because they emphasize things such as literacy, numbers and social skills," Garrison told HealthDay.

HealthDay points out that during the study, researchers did not attempt to reduce the number of hours kids watched TV before bed, they only aimed to alter the type of shows kids watched.

But, Garrison warns, that doesn’t mean letting kids watch age-appropriate shows prior to bedtime is a good idea. In a previous study, she found that “found that kids who used media (any TV or video games) around bedtime were more likely to have sleep problems than kids who abstained,” TIME Healthland reports. She recommends that parents power down at least an hour before kids go to sleep.