Riding motorcycles on slippery surfaces is dangerous and takes practice. You only have 2 small patches of rubber that separate you from the ground, so maximizing their use in adverse situations is key to safety.
Lets assume you are riding along a road you've never been on before, and you notice a metal-grated bridge ahead. Do you know how to get across it safely?
If you stay calm, don't over-react or make any sudden inputs, and plan your line, crossing a slippery surface on a motorcycle can be easier than you think.