Speaking to the crowd as he accepted his trophy, Mr Grylls said: “And also Prince George, your first ant you ate today.
“And that is a great moment. Well done, you.”
According to The Sun, upon hearing her son had eaten an ant the Duchess of Cambridge doubled over in laughter.
Another eventful moment of the day was when a sassy Princess Charlotte stuck her tongue out at onlookers.
Prince George looked cute as a button in a Breton-striped top, and even wore a sailor's hat for part of the regatta, while Charlotte wore a striped blue dress.
Kate and Wills were competing against each other all in the name of charity, with the Duke and Duchess of Cambridge skippering their own boats of six celebrity ambassadors.
Although each of the celebrities was representing their own charities, Kate sailed for the Royal Foundation while William battled it out for Child Bereavement UK.