Why does it take a long time to breed Riolu?

Question

My Riolu is in the Day Care Center and he is with a Ditto, but I've been waiting for 3 days for an egg and there hasn't been one. Why does it take a lot longer for some Pokemon than others?

Answer 1

As DD said, Riolu cannot breed. When you put pokemon in daycare you should talk to the man outside. If he says "They prefer to play with other Pokemon more than each other" then they will never mate.

Anything else he says means they will mate, even "They don't like each other". It will just take longer.

Answer 2

Riolu is one of the baby Pokémons, so it CANNOT breed

Answer 3

Try to breed lucario instead it might work better.