Fell out of base & got surprised by one at night. My dinos out of reach oO. I was lvl 60 wearing Flak & lether. Couldnt react fast enough & rapidly fell unconcious... thought thats it. I'm dead. Hardcore server... BUT: My Mesopiticus Lvl 38 was my Hero! He did not only pulled Troodon away, he actually killed it! Seconds before I'd have dies. Small one really made my day!!
At lvl 72 with flak armor on, a lvl 5 Troodon knocked me out with one attack at night. Last thing I saw was those glowing eyes before passing out. My Guess is that they attack vital organs. Luckily my Doedicarus was up for a game of baseball and launched that little devil out into the stands.