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.
In order to tame a trodon, you must sacrifice a tamed animal, beter during the night, and the bigger the tame, the better the taming effectiveness, what i suggest ia that you breed baby dino's and trap the trodon before hand,the best to sacrifice to the trodon is a giga and i suggest a baby for a low risk.