If a female tiger has had cubs then the cubs are in risk of being eaten by an adult male tiger. The male tiger will eat the cubs so then the female tiger will become in heat again as she won't have...
Its called 'growing up', you maybe new to the concept
they usually have 1-7 cubs
Up to four every two years.
Tiger cubs usually leave the care of their mothers at around 1 and a half - 2 years