Employees are struggling with burnout, but taking time off isn’t always that easy. For its latest report on out-of-office (OOO) culture, the Harris Poll surveyed 1,170 American employees over the age of 18. It found that employees not only struggle to ask for time off, but often feel guilty when they do.

What do they do instead? According to the survey, many are coming up with work-arounds to play hooky at work. Here are some of the key findings.

• It’s a culture problem, not a policy problem: 83% of respondents said they are happy with their employer’s time-off policy and 60% get more than 10 days off a year. However, 78% don’t use all of their days off. The average American took 15 days off last year, although about half have more than 15 days off a year.
• Workers, especially younger ones, are afraid to ask for time off: Half of employees said they get nervous asking to take time off. (This increases to 61% for millennials.) In fact, 76% said they wished their employer placed more emphasis on the value of taking time off.
• Out of office doesn’t mean rest: While 62% of people say being out of office means not working, 60% say they struggle to fully disconnect, and 56% have taken work calls or meetings during their time off.
• Bosses share the blame: Nearly 90% of employees said they have read emails from their boss, and 47% say they feel guilty taking time off.
• Employees are coming up with their own work-arounds: On average, 31% have moved their mouse to keep their status active on their company messaging system. Meanwhile, 30% have scheduled messages to send outside of working hours to create the impression they are working longer; 28% have taken time off without telling their manager.
• Especially younger ones: Nearly 40% of millennials—the group most terrified of asking for time off—admit to using these work-arounds.

“The data underscores a nuanced challenge in today’s workforce: the pervasive fear of being ‘out of office’ and the difficulty in fully disconnecting,” said Libby Rodney, The Harris Poll’s chief strategy officer and resident futurist, in a statement. “As we navigate an increasingly connected world, it’s crucial for individuals to set boundaries and for employers to support their employees in achieving a healthy work-life balance.”