The children's questions that parents find it toughest to answer. Basic questions from children about the planet, outer space and the human body leave most parents unable to give a correct answer, according to a survey of 2,500 parents.

Top of the list is "how is electricity made?", "what are black holes?" and "what is infinity?" Other baffling questions in the top ten include "why is the sky blue?" "why do we have a leap year?" and "how do birds fly?" and "where do babies come from?”

Of those who opt for myths instead of truths, seven in ten parents use the explanation that "babies are delivered by storks" and 23 per cent say "babies are found under gooseberry bushes". Other popular answers include "babies come out of your tummy button", "I found them" and "babies are bought in Tesco at night on the top shelf by mums and dads only." The survey also reveals the common age for parents to tell their children the truth about reproduction is 10 years old.

It also shows that parents find moral questions about God and religion hard to answer. When asked "where do you go when you die?" four in ten parents told their children they go to either heaven or hell, with 25 per cent of parents saying that "you become an angel".

The study reveals that modern day parents are increasingly turning to the internet to answer difficult questions from their children - 56 per cent said they use the web.