they will live providing they dont get eaten by anyother fish. the adult guppys will eat the young ones (fry). i did start with putting mine in a breading net but stopped doing this as they were just havin baby left right and centre. the fitest will survive. if you have plenty of hiding places you should be ok
it depends how big the tank is and how many hiding places you have
i leave mine in the tank and sometimes i get about 10 other times i dont get any its just luck if they can hide from the adults until there big enough they cant eat them
In my only guppy tank I see a few survive each drop. I have a good sized clump of java moss in the tank so the fry have a place to hide but I do nothing to save them except to keep the adults properly fed. Most guppies are not voracious fry eaters but that does not man a tank full of adult guppies is safe for a fry to swim through. It is one of the real differences that I see between the guppies and my endlers. It is not unusual to see a newborn endler swim right past a full adult endler as if it wasn't even there and survive the encounter. I see it every time I feed the endler tank. All of the fish are out eating and are ignoring everything but the fish food in their feeding frenzy.