The 'Angels' hitmaker has previously claimed to have spoken with spirits and been visited by aliens, but he's convinced they've all abandoned him since he had his kids; Teddy, seven, Charlie, five, Coco, 18 months, and one-month-old Beau with wife Ayda Field.
Speaking on a US radio station, according to The Sun newspaper's Bizarre column, Robbie said: "The strangest thing is that since I've had kids, the phenomena has ceased to happen. I'm guessing that once you have kids they just take up all of your energy and your thoughts."
The 46-year-old singer - who currently lives in Los Angeles with his family - was told from a young age that he could communicate with the dead.
He explained: "I was told at a very early age that I used to see people that had passed on and I would talk to them. That kind of carried on through my youth.
"Then I stopped talking to them because I found drugs.
"I came out of the womb a Catholic, so you're told all these amazing stories about this incredible man who walked on water and, you know, made scampi for everyone. So you're already open to the possibility of the paranormal. My mum had these books on her shelves about fairies and UFOs, so my mind has already been open to this stuff."
Robbie is so fascinated by extraterrestrial life that he was toying with the idea of buying Utah's Skinwalker Ranch - which is known for paranormal and UFO-related activities - but decided against it because his wife Ayda wouldn't have approved.
He said: "There were big rumours on the internet that I'd bought the ranch. That's the kind of dumb stuff that I'd do and not tell my wife. She knows I didn't do that and now the whole world knows I don't own it. But if I didn't have a wife, I would have bought the ranch."