They hide among the plants when they are stressed or going into labour. Do not disturb them or move them otherwise they can abort the babies and they die. Just leave the females in a well planted tank and scoop the babies out after they are born. Use a plastic container/ cup to scoop the babies up in some tank water and put them in a breeding net or rearing tank.
If you only have platies in the tank and you feed the adults well, they usually leave the babies alone and they can grow up with the mother.
The babies can be fed on finely crushed flake food and newly hatched brineshrimp. The following link has information on hatching brineshrimp eggs.
STARTING OUT Make sure you have a pair, (1 male + 1 female). There is nothing worse than spending your hard-earned dollars buying a couple of fish to try and breed and ending up with a pair of fish of the same sex. Let's face it, to reproduce fish you need a male and a female. Two males won't do...