When Brainerd, Minn., school officials can't find a substitute teacher, they get creative.
That can mean asking teachers to give up preparation time to cover for a colleague.
"We've had to have them come into the other room that we may have not been able to fill a sub in and cover the classroom for that portion of the day," Superintendent Klint Willert said.
In his scramble to find substitute teachers, Willert joins school officials across Minnesota. Teachers are in high demand because fewer people are entering the teaching profession.
But when it comes to finding substitutes, schools have another big problem. The strong job market has made the part-time work a tough sell.
The young teachers school districts often relied on as substitutes now have full-time jobs. Others who may have served as subs in the past are finding reliable full-time jobs outside of teaching.
"They might opt instead to go work at a location that provides them with some guaranteed income and guaranteed hours of services," Willert said. "When we call a substitute, we can't do that."
When the Minnesota Department of Education recently surveyed school officials around the state, 90 percent said finding substitutes was "somewhat difficult" or "very difficult."
As a result, school districts are trying to find new ways to attract subs. The St. Cloud Area School District, for example, has explored new ways to recruit.
"We got a little proactive and decided to have a job fair that's specific to substitute teachers," district spokesperson Tami DeLand said.
After holding the event in November, the district has 20 new short-term substitutes to call on.
To serve as a short-term substitute, teachers need a four-year college degree and a substitute teaching license from the state. The St. Cloud district also requires them to take training on how to handle a classroom to boost their confidence in front of students.
The district also gave 13 long-term substitutes in a newly formed "guest teacher" program contracts through the end of the school year.
Their job is to show up every day and sub where needed, Deland said.
"For the most part, those teachers would be assigned to a given building and obviously their daily pay would be higher," she said.
The long-term subs in St. Cloud make $180 a day and help alleviate the daily school staffing scramble.
Low pay and the lack of benefits also contributes to the shortage of willing substitutes.
Pay ranges from $45 a day in rural areas to $100 or more in urban areas, according to the Substitute Teaching Division, a Utah-based organization that provides sub training across the country.
To sweeten the deal, schools sometimes add little bonuses like free tickets to school plays or football games, said Geoffrey Smith, the group's director.
"I talked to a superintendent just last week who said, 'We give free lunches to all our substitutes,'" he said.
Turning around the sub shortage will likely take more than free lunches. In coming years, Smith said, schools will need to intensify their efforts to reach out and recruit new substitute teachers.
Smith also notes an increase in the number of districts outsourcing their subs. But he thinks that's a reaction to the federal Affordable Care Act rather than the shortage of available substitutes.
Under the ACA, districts are required to pay for health benefits if their subs work more than 30 hours a week.
One such company, Teachers on Call, is based in Bloomington. Among its clients are 42 school Minnesota school districts, including St. Paul's. It also serves 33 Wisconsin districts.
National studies on teacher absenteeism in the last decade show 5 to 10 percent of teachers are out each day, on average.
That's about how many open spots Kevin Groebner, principal of Jefferson High School in Bloomington, had to fill on a recent day.
"I've got my sub list here," he said. "One, two, three, four, five, six."
On any day of the week, as many of six of the school's 85 teachers are out.
But Groebner has an ace in the hole with Rich Bird, a substitute teacher on contract who comes into work every day.
Bird, who recently filled in for a teacher in a TV production class, has been a full-time substitute at Jefferson for eight years. He signed on after his 2005 retirement from the school, where he taught English since it opened in 1969.
Although the job is a good one for a retired teacher, Bird is not sure it would be attractive to someone trying to make a living off $140 a day. But it does keep him busy.
These days, he covers a variety of other classes — from chemistry to Spanish and anything in between.
"I just come in every morning and go where needed, basically," he said.