Young IT employees pose a challenge to many managers who say the Millennial generation holds employers up to unrealistic expectations and makes unreasonable demands for their services.

Millennials -- employees between the ages of 18 and 31 -- represent the top challenge for IT managers, according to survey results released Thursday from Atlantic Associates, an IT staffing company. (See what IT veterans think about this study here.) 

Atlantic Associates polled more than 100 Massachusetts executives on the challenges they face and more than 50% of respondents described those teen and 20-something employees as the "toughest generation to manage." Generation Xers (ages 32 to 42 years old) placed second with 17% of respondents saying they pose a management challenge.

Jack Harrington, co-founder and principal of the staffing firm, says the problem between employers and the younger generation just entering the workforce can be traced back to the employees' upbringing or an easier way of life for children in the United States today.

"The issue managers are facing is with retention, not hiring. That means the work environment is not living up to the employee's expectation," he says. For instance, many younger workers expect to get an office immediately or be paid at a rate higher than entry level.

"Millennials are coming in with high expectations and are disillusioned about the reality of a work place. They feel they should be rewarded and start at the top, when we all know you have to work your way up. They have been raised to be rewarded often and when you get into the workforce those rules change a bit," Harrington says.

But Millennials' ideas also have a positive influence on work environments. For instance, they expect their employer to be socially responsible and take part in community or philanthropic ventures, which is a good thing, Harrington says.

"To reach a good working balance, Millennials will have to change their ideas somewhat, but the work environment will also change to appeal to these very in-demand employees," he says.

With baby boomers retiring, fewer IT graduates and low unemployment rates in high-tech fields, the executives polled reported that hiring and retaining qualified candidates is the primary staffing challenge they face this year. Twenty-three percent of respondents said retaining existing staff is the top concern, while 22% said they struggle to find new qualified candidates.