Children are frequently using social media even though they are below the age restriction, research released to mark Safer Internet Day 2016 has revealed.
Among 1,000 under-13s surveyed, 78% admitted to using at least one social network on a regular basis, the small-scale study by BBC Newsround found.
Both Facebook and Instagram state that users must be at least 13 years old, however these were found to be the most popular social networks for children aged 10 to 12 - with 49% of under-13 social media users claiming to have a Facebook account, and 41% having an Instagram account.
In their study of more than 1,500 13- to 18-year-olds, the UK Safer Internet Centre found young people want the internet to be a positive and inclusive place that respects people’s differences, with 94% stating they believe no one should be targeted with online hate.
One of the main findings was that one in four teenagers are being "trolled online".
However it wasn't all bad news, as the study also revealed young people found social media to be a place to join and support certain groups, such as LGBT people, disabled people, or those of a certain race or religion.
Will Gardner, director of the UK Safer Internet Centre and CEO of Childnet - an organisation dedicated to online safety for kids - said with an increasing number of children on social media, we need to make sure it's a safe place for everyone.
"It is a wake-up call for all of us to play our part in helping create a better internet for all and empowering everyone to be able to express themselves and be themselves – whoever they are," he said.
Peter Coe, an academic and lecturer in Law at Aston University, said social media skills are becoming engrained into children's minds and will be useful for the world of work when they come to it.
He said what needs improving is children's "online health", referring to how children portray themselves online.
"Increasingly, young people are struggling to cope with cyber bullying, trolling and pressure to post things that they might not be entirely comfortable sharing," he said.
Coe has developed what he calls the "green cross code" as a good way for children to start thinking about the way they are engaging on social media.
He used the acronym 'PAUSE'.
(P) Remember that everything you put online has the potential to be seen by anybody and everybody and that it can be PERMANENT.
(A) Before posting, tweeting, sharing, texting or uploading think about your AUDIENCE and how it could affect them and/or their opinion of you and others, now and later on.
(U) If you are still UNSURE ask for a second opinion from somebody you trust. Equally, if you receive a text, tweet, message or picture that you are UNSURE about tell somebody you trust.
(S) STOP AND THINK what impact your online activity may have on your privacy or reputation, or the privacy or reputation of others. Remember (P).
(E)If you are uncomfortable with anything that’s been tweeted, posted, shared or uploaded END your involvement immediately and tell somebody you trust.
Coe added: "The acronym, PAUSE, is in itself good advice, encouraging young people to detach from the immediacy of social media and avoid the potential pitfalls of a fleeting or emotional response.
"An awareness of the permanence of posts is vital, so that the seemingly acceptable or inconsequential doesn’t undermine your reputation down the road.
"As we teach young people the birds and the bees of social media, encouraging them to keep one eye on the future should be a big part of it."