LAWN DAMAGE

I posted recently about bird damage to my lawn and chafer grub was/is the culprit. I treated the lawn with the recommended lawn grub killer and now two weeks on the birds are still active and the grubs still alive; am I being impatient in expecting the treatment to work in two weeks? I shall give the lawn another treatment - my question is about the dozens of small holes in the lawn; in your experience will the lawn recover by itself when the problem is sorted.,,,,,although I understand the grubs eat the roots so I guess some reseeding will be necessary - your advice on how best to proceed would be appreciated. I have little or no knowledge of lawn care save mowing, although I have scarified the lawn in an attempt to make things a little better (or worse maybe).
Many thanks.
Posts
Christopher2 - many thanks. The lawn was well watered after treatment and we had a day of rain; dilution was as per pack directions. I'll rake the lawn and re-treat.
Thanks again