Hahahahaha! I encountered my first batch of chryssalids ever today... man, did I get an asswhooping

It started out like with me facing about a dozen of snakes which I disposed pretty easily. Then when I saw the first chryssalids I shot them down fairly easy UNTIL one of them snook up on my 5 men squad. Only one of the poor guys survived :P
It ended up with only 2 guys surviving the mission (out of 14!) and I'm still wondering if I should reload and play it again or lick my wounds and suffer the losses. Any tips on fighting chryssalids in general?