A better way -- The -T Option

The -T (same as --timing) switch offers 6 "canned" timing levels.  From -T0 to -T5.  Or you can use the long versions below:

-T Paranoid -- 1 Probe every 5 minutes
-T Sneaky -- 1 Probe every 15 Seconds
-T Polite -- 0.4 seconds between
-T Normal
-T Aggressive -- Recommended when you're in a hurry
-T Insane -- Warp speed!  Be careful!