What do these fields do? (locust swarm)

1) Damage Return Factor
2) Max Swarm Units Per Target
3) Number of Swarm Units
4) Data - Unit Release Interval (seconds)

I was trying to make a modified (more powerful) locust swarm with multiple levels for my hero siege map but why are there so many damn fields lol. I don't really know which fields to edit and what types of values to use because its a hard spell to test. Anyhow, thanks guys.

-Huh

How much of the damage that the Locusts do is given to the crypt lord to heal him when the locusts return.
The maximum number of locusts that are allowed to attack one target. If you set it to 999 or whatnot, all of them can attack one target, creating a rather devastating effect.

How many locusts there are.

When the spell is cast, it releases a locust. Then, it waits x seconds before releasing another, and so on. The unit release interval is x.

Ok thanks, I'm still a tad confused as to how the spell works overall but I guess ill play with it some to see how deadly I can make it ^_^