"Why is the moon is out during the day" and "Why is the sky blue" are questions that parents most fear from their children, according to a new survey.
Researchers found that two thirds of parents are often stumped for an answer by their children’s questions, particularly on mathematics and science.
Aside from those on the moon and sky, they found the most perplexing demands also included how aeroplanes stay airborne, what makes a rainbow and why there are different time zones.
The natural world featured in a list compiled by the researchers with questions on the apparent disappearance of birds and bees in winter.
However, there were more esoteric queries, including whether aliens will ever be found, how much the Earth weighs and why water is wet, the Telegraph reported.
A quarter of mothers and fathers admitted to feeling frustrated and embarrassed by their intellectual shortcomings, the survey found.
The nationwide study was commissioned for The Big Bang UK Young Scientists and Engineers Fair, which describes itself as the UK’s largest such event for young people.
Around 2,000 parents took part and one in three said they were asked scientific or mathematic questions by their children on a daily basis.
Half of parents said they were worried about answering their children’s queries on those subjects.
One in three admitted to furtive researching to save face before answering their child.
A fifth of people said they either invented an answer or claimed no one knew the truth and 16 percent of respondents simply passed the query to the other parent.