[@POOHEAD189]Either that or he's very certain about his statement :P

But yeah, in terms of DNA they're Dextro-amino acid based life forms, I think intercourse between them and a human requires something like tablets or ointments to prevent a rash occurring from contact with fluids, don't know my knowledge on their biology is spotty at best.
I only say that they're not physically adept as in terms of their prowess in technology, they're more likely to use tech to defeat their foe rather than suit up in armour - a big gun can stop a Krogan but no amount of plating can stop them from tearing your limbs off and beating you to death with them; if you catch my drift.