Combat: Wind sprites normally avoid combat, and don't have a very effective attack anyway, at least by themselves. They will only fight to defend themselves. Wind sprites have unlimited "gust of wind" capability, and for every 3 sprites present they can coordinate their wind gusts doing a total of d6+1 hp, victims must save vs. breath weapon or be knocked over and spend their next round recovering. A group of 9 sprites can lift man sized creatures up and blow them 2d10 feet, and do 3d6+3 damage. A group of 9 sprites can also capsize boats shorter than 30 feet. Wind sprites can also be captured in a bottle on a successful attack roll. Once released, that specific sprite will always be wary and will use its fantastic movement rate to ensure it is never captured again.
Habitat/Society: In large groups, wind sprites can become rowdy and blow things (and people) over for the fun of it. (only does damage if the sprites are defending themselves) However most of the time they are more sedate, and are content to ride along with the wind. Often when people think they hear the wind whistling, it is actually wind sprites having a good time. Captured wind sprites will promise to serve their captors if released, and can change winds from chart 79 on page 127 of the DMG up or down one category. They will only want to serve for one day, but if their captor forces them to promise to serve for longer, there is a cumulative 10% chance per day over 1 that the sprite will hold a grudge and return d4 days later with 5d6 friends and try to do their former captor harm. In order to mollify a mistreated sprite, they can be given gems. Each 10gp the gem is worth reduces the sprite "grudge percentage" by 10%. The sprite must be mollified before it comes back with its friends, otherwise they'll all want a gem. Once a sprite has a gem, it absorbs and dissipates it. For the next week, the sprite becomes slightly visible, in the colour of the gem they were given.
Wind sprites are incurable gossips. When ever they blow through a place where people live, they are sure to keep their ears peeled for the latest dirt. If captured and questioned, wind sprites may have some information about people or events within d100+50 miles in the direction the wind is coming from. However, this knowledge is very random and could either be important, or local gossip about what one farmer said to another. Wind sprites are not good at telling what a person might find important or not. Besides this, a sprite captured against its will will tell its captor just about anything to get loose.
Ecology: Wind sprites don't mind snacking on gems occasionally, and may (45%) eat any they find out in the open. They pick up enough water by sometimes blowing through clouds. On death, a wind sprite dissipates into normal air.