Here's a good fact...
Did you know that infant/youth T-rex have a mouth full of deadly bacteria. Their bite would not be all that dangerous to the majority of dinosaurs, but if they pierced the skin and allowed the bacteria to enter the bloodstream...a painful septic death for the unfortunate attacker.
-Think twice about attacking small animals- they haven't been eaten yet for a reason.
-Infants are not just little adults, they are often very different in their physiology (yes...this includes humans too- topic for another post)