The Mirror newspaper in Britain said Terri Irwin, Steve Irwin's widow, confirmed their son, Robert, was nipped by a boa constrictor.
"He picked one of them up and it bit him on the finger. He was so proud to have copped his first hit. He said, 'I hope it wasn't venomous,' so I assured him I wouldn't let him play with venomous ones," Terri Irwin said, adding Robert's big sister, Bindi, was first bitten by a snake when she was 18 months old.
Steve Irwin, known as the "Crocodile Hunter," died in 2006 at the age of 44 when he was pierced in the heart by the barb of a stingray while snorkeling at Australia's Great Barrier Reef.