The Platypus layes eggs in a burrow that it has carved into the river bank. It can leave them to go swimming and they will still be fine heat wise when it gets back. When the eggs hatch the mother has glands that leak milk and the infant sucks on them.
The poison that the platypus has is created in a gland in its back legs. It has a spur next to its toes which it can use to kick out at anything attacking it. This poison is only used in self defence and not to capture prey. It eats shrimp and crayfish using its bill to sence for the electric impulses that its prey give out.