Some pest control products sold in local markets may not be safe. If a product contains the active ingredient dichlorovos or DDVP be aware! This chemical is HIGHLY TOXIC and no products containing it should be used.
If you are hiring someone to spray your yard for mosquitos, it's a good idea to check the labelling of the spray used. It's not uncommon for the wrong product to be used, as some go by the pictures and do not understand the labelling.