Bill O'Reilly thinks dogs don't have knees and he's using that to attack liberals on Instagram.

Let's get this out there: dogs have knees. Corgis have knees. All dogs have knees. Even Bill O'Reilly's dog, Holly, has knees, no matter how many non sequitur statements her owner makes about the national anthem and her inability to kneel for it.

"Holly would never take a knee during the National Anthem," wrote Bill O'Reilly, at least a week after the kneeling during the national anthem controversy reached its apex, "even if she had knees."

He's referring to the fact that many NFL players have chosen to kneel in protest of racial inequality, police brutality, and Trump's statement that anyone engaging in this peaceful protest is a "son of a bitch."

Again, just to clarify: dogs have knees. A fact that Full Frontal host Samantha Bee clarified on Twitter.

And which sparked something of a debate in the comments, although even the staunchest dog-knee-truthers were eventually convinced.

Bill O'Reilly was fired from Fox News after the New York Times reported that he and the network "had paid millions of dollars over the years to settle claims of sexual harassment and other inappropriate behavior made against him," according to CNN.

In related news, here are "11 surprising facts about corgis." None of which are that corgis don't have knees. Again, they do.