Any harm in mixing deer repellent and insecticide for only 1 spraying? (plants, Chapel Hill)

[no kudzu]

Ok- I don't use many chemicals in my garden but we have some major problems with deer, ticks and japanese beetles. I've been using sevin dust for the beetles which makes the plants look horrible. I spray for the deer and finally decided to use spectracide for the ticks. Any reason why I can't combine the deer repellent and spectracide for one sprayinfg without blowing myself up?
Any other suggestions for ticks? They are really bad and it is not a coincidence we have lots of deer and lots of ticks. I have young children and we inspect the whole family every night for ticks. I'm beginning to get scared witrh all the lyme disease and other tick borne diseases. I'm in Chapel Hill NC.

[Rtom45]

Most chemicals will tell you somewhere on the label what mixes and what doesn't. Failing to find that, you can usually mix a small amount of the chemicals you intend to use (again the label should give you some guidance) and do a test patch. Typically if you get any kind of cloudiness or residue in your sprayer the chemicals are not compatible. Also what you may not see or may not be able to measure, is a reduction in effectiveness when things are mixed.

[no kudzu]

thanks Rtom45- i never thought about reduction in effectiveness. I was more worried about mixing something combustible-guess I'll just have to make multiple spraying trips around the yard. Any special recommendations about tick control in NC anybody?