If your workplace is anything like ours here at CareerBuilder, once the leaves start to fall, the office becomes riddled with sniffs, coughs, sneezes, shouts of “Gesundheit!” — you get the picture. Trash cans overflowing with tissue aside, though, you’re probably well aware that some employees who call in sick may actually have other reasons for being absent from work, whether it’s a mental health day or a holiday shopping trip. This year’s CareerBuilder survey about absenteeism finds that January-March are the most popular times for workers to call in sick, 29 percent of workers have admitted to playing hooky from the office this year, and that if you thought 2010′s most unusual excuses for missing work couldn’t be topped,you need to check out this year’s contenders.

INFOGRAPHIC: Are employees sick — or do they have the 9-to-5 bug?

Chilly days and empty desks

The survey of more than 2,600 employers and 4,300 workers found that, while employers reported heightened absenteeism around the holidays, the first quarter is the prime time of year for employees to call in sick:

• January through March — 34 percent
• April through June — 13 percent
• July through September — 30 percent
• October through December — 23 percent

“So sick, can’t be @ work TTYL”

How do your employees inform you that they’re not coming into work? Turns out, it’s becoming more common for employees to contact the boss through methods other than the traditional phone call. The legitimacy of this, of course, depends on your company or departmental rules, though as some bosses respond more on one medium versus another, it does make sense that more workers are relying on digital communications to get their message across. How do you feel about employees emailing or texting you to tell you they’re going to be absent — are both or either OK?

• Phone call — 84 percent
• Email — 24 percent
• Text message — 11 percent

2011′s most unusual excuses for missing work

• “My 12-year-old daughter stole my car and I had no other way to work. I didn’t want to report it to the police.”
  
• “Bats got in my hair.”
  
• “A refrigerator fell on me.”
  
• “I was in line at a coffee shop when a truck carrying flour backed up and dumped the flour into my convertible.”
  
• “A deer bit me during hunting season.”
  
• “I ate too much at a party.”
  
• “I fell out of bed and broke my nose.”
  
• “I got a cold from a puppy.”
  
• “My child stuck a mint up his nose and we had to go to the ER to remove it.”
  
• “I hurt my back chasing a beaver.”
  
• “I got my toe caught in a vent cover.”
  
• “I had a headache after going to too many garage sales.”
  
• “My brother-in-law was kidnapped by a drug cartel while in Mexico.”
  
• “I drank anti-freeze by mistake and had to go to the hospital.”
  
• “I was at a bowling alley and a bucket filled with water (due to a leak) crashed through the ceiling and hit me on the head.”

Peeping employers

Many employers take calling in sick without a legitimate excuse very seriously. So seriously, in fact, that 15 percent of employers said they have fired a worker for this reason. Twenty-eight percent have checked up on an employee — sometimes in cringe-inducing fashion. Of that 28 percent:

• 69 percent required a doctor’s note
• 52 percent called the employee
• 19 percent had another employee call the employee
• 16 percent drove by the employee’s home

But are some employees telling tall tales simply because they’re afraid employers can’t handle the truth (that they’re just overworked, or overtired, or way behind on life outside of work with all the work they’ve been doing)? As I’ve said before, it often comes down to trust and communication; while employees should be honest, employers should also be open and communicative about policies and preferences for work absence.

Let your employees know what your expectations are. Is it OK for an employee to tell you he wants a day at the zoo with his son, for example? By trusting and respecting your employees, they’re more likely to return the favor. And keep in mind that sometimes, taking a mental health day to catch up on sleep, spend time with family, or indulge in a day at the spa may be just what the doctor ordered for your employees — and the best thing for your business.

Rosemary Haefner, vice president of human resources at CareerBuilder, offers her thoughts:

“While outrageous events are known to happen, frequent absences and over-the-top excuses can start to bring your credibility into question. Many employers are more flexible in their definition of a sick day and will allow employees to use them to recharge and take care of personal needs. This is especially evident post-recession when employees have taken on added responsibilities and are working longer days. Your best bet is to be up front with your manager.”

Employers, what say you? Do you agree with Haefner that employees deserve more flexibility with their added duties, and that a “sick day” can be a day to rest, recharge or take care of pressing personal matters, as long as employees are honest about it?