Question
what can i do to get ride of tiny grass flies? it seems they love the new sod i just layed.
could i use some type of insectiside or fertilizer? keep in mind i have small children that love playing in the grass. thanks in advance for your assitance.

Answer
Flies and moths on the lawn are generally not harmful to turf or humans. There are bound to be exceptions but I have not heard or read of any. But flies and moths are the adult stage. Before they become adults, there is the caterpillar or larva (which hatch from the eggs of moths and butterflies) or grub (from the eggs of flies and beetles). That is the stage that does they damage. Flying insects on the lawn now are a nuisance (harmless in most cases) but the females are laying eggs and soon the will hatch out into one of the stages that might feed on the grass blades or roots. If you can identify the moth/fly now you can learn, from its life cycle, when to expect the the turf damage. This will put you in the advantageous position of being able to treat at the earliest stage of infestation.
From the aspect of safety, consider treatment with "Bt" - a Bacillus strain which gives caterpillars (and only caterpillars) a stomach disorder that kills them. The treatment is harmless to humans. There are other strains of Bacillus which target the larvae or grubs of other insects. Again, harmless to humans so your children can romp on the lawn without causing you  unneeded stress.