According to Jigglypuff's Pokédex entry, it will never stop singing until it's foe is asleep. That means that if a Jigglypuff encountered a Pokémon with the insomnia ability, it would endanger it's own life.
Hello. We are Cloyster Cave, a fansite created for you personal enjoyment. As of yet, the most exiciting thing we have is the above quote box. But we are soundly growing. With our thrilling story, Shadows of Legends, and our innovative Poetrydex, with the goal of having a poem for every Pokémon, we are building quite a repotoir of amusing, interesting and creative content. But there's just one thing you need to know-we are not a wiki. We are not open to everyone. We will allow you to make a creative piece here, whether it be a story, a game, or a drawing, but it must be approved. We're not too strict on this, but you will not be allowed to become a contributor 'just cause'. You will need an idea, first.
But with such an open and wonderful world as the one of Pokémon, finding ideas shouldn't be too hard!