That stuff must not work, after you spray I see lots of baby roaches!!
This is a common complaint of pest control clients--but not to worry. This complaint means that you are doing your job. When a surviving German cockroach deposits her egg case, more then 30 tiny nymphs are going to hatch from it so, the residual spray that is left should soon kill the newly hatched nymphs and the mother. However, if an egg case hatches weeks after your treatment, you may need to return and perform another treatment to maintain control.
Source: Techletter Vol 3. No, 240