A video game addict tried to poison his family after they unplugged the wi-fi to stop him playing at high volume at their home in Thailand.
Sak Duanjan, 29, returned home drunk and started playing loud games on his smartphone while his parents were trying to sleep in Sisaket.
His stepfather Chakri Khamruang, 52, got out of bed and switched off the wi-fi to prevent further disturbance from Duanjan.
The next morning his mother Suban Duanjan, 51, discovered lethal pesticides left floating on the water inside the family's well by the gamer.
The stepfather and son had rowed furiously after the wi-fi was turned off as Duanjan screamed obscenities and smashed up the house last Thursday.
Chakri Khamruang, 52, the man's stepfather and his mother (right) - they have involved the authorities as they do not know how to deal with Duanjan
Mr Khamruang had been forced to hit the younger man to get him to sober up, but the pair went to bed and he thought that would be the end of it.
Mrs Duanjan said she discovered the poison when she went to collect water for cooking rice in the morning.
The shaken mother said she was stunned her own son would try to kill her and her husband.
Mrs Duanjand said: 'I saw my son went downstairs and putting something on the jar around 2am. I asked him what he was doing but he didn't answer and returned to his room. So, I let it go and went back to bed.
'I still didn't believe that he could do this. I know that he gets angry very easily. We tried our best to deal with his anger but this time it has become too much.'
Mrs Duanjan discovered lethal pesticides floating on the surface of the water the next morning when she went to cook rice
The family decided to call the local authorities for help in curbing the son's violent behaviour.
Duanjan later admitted he had put the poison in the family's water supply because he was still seething after being prevented from playing his smartphone game.
The mother added: 'We wanted government officers to take him for treatment at the hospital because we don't want to live in fear wondering when he would attack us again.
'He plays on his phone so much, I think that's what makes him stressed. It's hard to stop him as he's a grown boy now. So we have asked for help.'