Why are some captured pictures (I didn't capture them before) in sdcard/com.facebook.orca?

I found some captured pictures in my cellphone. Files are in sdcard/com.facebook.orca. I have the original video of files but I didn't capture them. Also I've never used them on facebook and fb messenger before. I'm so worried about whether my personal video was sent to other. Why they are in sdcard/com.facebook.orca?