How long does it take a blue tit egg to hatch?

A blue tit egg typically takes about 12 to 14 days to hatch after the female has finished laying her eggs. The incubation period starts once the last egg is laid, as the female will then sit on the eggs to keep them warm. Conditions such as temperature and humidity can affect the exact hatching time. Once hatched, the chicks are altricial, meaning they are born blind and helpless, requiring care from their parents.