"At conjunctions of Nature and magic, the beautiful sprite is born beneath the petals of a flower under the light of the full moon."Summon Sprite is a first-level Nature Magic spell in Heroes of Might and Magic IV that costs two spell points and summons a number of Sprites based on the level of the caster.
Not a particularly useful spell as the sprites can't perform one of the basic functions of low-level summoned creatures soaking up retaliation damage. Still, the sprites high movement means the creatures can be used to divert incoming enemies from their path, giving you more time to soften them up with ranged attacks. To best use this strategy, turn movement shadows on, right click on the enemy stack to see the limits of their movement and then fly the sprites to either the furthest edge of the shadow or just beyond it - the former if the stack is close and will not be diverted if the sprites are not in attack range.
One thing sprites can do is fly up to and attack dangerous ranged units. Because the sprites attack doesn't trigger retaliation, the sprites will remain (at least until the unit or another on the same side swats them), and your other ranged units can then shoot their target with impunity.