That doesn't have any purpose but would be cool I think. For example, if you release it in the room with a candle or a built but unlit fire and the irrlight bumps into it, it should light it.
Maybe they even should sense such objects and fly towards them.
Even maybe if irlights bump into flammable objects such as hides for example, or wooden structures, they should have a chance to eliminate them or give some amount of decay.