With colds and the flu spreading around offices like wildfire, it’s hardly surprising that 62% of sick days are taken between November and February.

However, recent research from found that employers don’t always believe their staff are actually ill, with 40% of bosses checking up on employees to make sure they are actually sick.

While some employers are using standard procedures, such as requiring a doctor’s note for absent employees (65%), and phoning them to make sure they are sick (52%), others are resorting to less orthodox methods. Just under a fifth (18%) of those surveyed said they would ask a worker to phone them, 7% said they'd contact a family member. And, amazingly, 20% said they would drive past their house.

A third of employers (34%) admit to checking their employee’s social media posts to ensure they’re not faking their illness, and it’s a strategy that seems to work: over half (52%) of employees calling in sick falsely have been caught out through social media posts. Sixteen per cent of these were fired, and a further 29% were reprimanded.

“It’s important for employers to recognise that employees are more likely to be ill during the winter months and that they are likely to need time off to recover, or to prevent others catching their illness,” said Janet Prosper, HR Director of CareerBuilder EMEA.

“Giving them time off to recover fully is the best way to ensure they are back at full strength as soon as possible, but it is sensible to try and avoid abuse of the system. Having a clear sickness policy in place, requiring employees to phone their line manager directly on each morning that they are ill, and requiring a note from the doctor after three full days of absence can help ensure employees are genuinely ill.”