I've noticed, or think I have, that mowing the lawn regularily keeps the tick and chiggar numbers down.
This year we have them in the yard though. A hose end sprayer, application of insecticide will get rid of them for the season. use one that kills bugs in the ground where they winter, and breed.
At campgrounds, if one RVer in one site would spread some insecticide it would probably knock them down for the season.
I know lots, of Folks say it harms the environment, from their apartment,in the city.
We used coal oil around ankles and on pants, in the country. Gaiters sprayed with repellent should stop them getting on you.