That is just awful. I will certainly be getting my yard sprayed again. Where I live ticks are just a part of life. My kids know to check themselves all the time when they come in from playing outside. Very scary stuff. If would be only too easy to miss one.
I have been using a couple of sprays. I really wish we could develop a seriously poaerful tick killer, they are very dangerous and we aren't focused on reducing the threat other than "check yourselves" which doesn't always work.