Ignoramus10329 wrote:
Somehow we have a house fly invasion going on right now.

What would be a safe way to kill them all, that would be child and
baby friendly. Thanks.

i

Some rodent probably died somewhere in your house.

Anyway, in addition to what's been suggested, those electric fly
swatters are kinda fun.

If you want to impress people and don't mind a little fly on your hand,
use the Boston Swat (I think that's what it is called). Hold your
hands about 2 feet apart palms facing each other centered a couple
inches over and just a little behind a fly.

When you slap your hands together, the fly will seeming jump right into
your hands. Once you get the technique down, you'll have a near 95%
kill rate and no mess on the walls. Just wash your hands afterwards.