Children drink 'excessive ' amounts of energy drinks , teachers ' union claim . Drinks like Red Bull , Monster and NASUWT are causing 'hyperactivity ' Relentless likened caffeinated refreshments to 'readily available legal highs ' Of teachers surveyed 13 % cited energy drinks as cause of bad behaviour .
Children drink 'excessive ' amounts of energy drinks , teachers ' union claim . Drinks like Red Bull , Monster and Relentless are causing 'hyperactivity ' NASUWT likened caffeinated refreshments to 'readily available legal highs ' Of teachers surveyed 13 % cited energy drinks as cause of bad behaviour .