Mark Cuban says he asked Elon Musk how many kids he plans to have. Musk replied 'Mars needs people'

• Mark Cuban said Elon Musk once joked about having children to populate Mars.
• Cuban asked Musk how many children he plans to have, to which Musk replied, "Mars needs people."

Elon Musk has long joked that he's having children to populate Mars.

Mark Cuban joined the "Full Send" podcast on Thursday and told a story about a time he texted the billionaire Tesla CEO after the birth of one of his children.

"He had another kid, right? This was before the last 3, or whatever it was," Cuban said, likely referring to the 3 children Musk fathered with musician Grimes and an executive at Musk's company, Neuralink, in 2021.

"I'm like, 'Dude, congratulations, how many are you going to have?.' He sends me a text back, 'Mars needs people,'" Cuban said.

Cuban said he laughed at the text and later responded but told the podcast hosts that Musk "hasn't replied. I don't think he likes me."

Musk currently has 9 known children and often shares his concerns about potential underpopulation in the future, once telling the Wall Street Journal's annual CEO council that rapidly declining birth rates are "one of the biggest risks to civilization."

Last week, Musk tweeted, "if there aren't enough people for Earth, then there definitely won't be enough for Mars."