Andrew Lorey, 29, and Samantha Thomas, 28, of Penlan, Wales, said their son, Jenson Lorey, vanished from the family's living room Monday night while his father was in the kitchen and his mother was at the gym, walesonline.co.uk reported Thursday.
"I started screaming and running around the street," Thomas told the South Wales Evening Post. "I thought the worst had happened."
"We had 12 police officers out looking for him, police dogs and the helicopter," Andrew Lorey said. "They searched the attic, they searched everywhere. Everyone who knew me was out looking but even people who didn't know me were looking too. It was just incredible -- the support we had was phenomenal."
After more than an hour of searching, the couple's daughter, Sienna, 6, discovered her brother sleeping beneath a beanbag chair in the living room, The Mirror reported.
Thomas said the beanbag had been moved several times during the search, so the boy could not have been under it the entire time.
"All we know is he was sleeping soundly when we found him," she said.