Walking through a central Texas pasture in the summertime will often result in getting attacked by ticks and chiggers. What I have always wondered is how these little buggers survive without hosts. In the pasture I am most often in (320 acres) there is only about 23 head of cattle or so. Add your occasional deer and coyote and there still wouldn’t would be enough blood for all those thousands upon thousands of pests. How do these guys survive?
Texas mammals.
http://www.tpwd.state.tx.us/nature/wild/mammals/mammals.htm
Picking out the “Central Texas pasture” type mammals (omitting, say, cetaceans, and beavers…)
Chipmunks.
Ground squirrels.
Prairie dogs.
Shrews.
Moles.
Hares.
Rabbits.
—> Armadillos. <---- 
Pocket gophers.
Kangaroo rats.
Pocket mice.
Other rats and mice.
Porcupines?
Weasels.
Foxes.
Feral dogs.
Skunks.
Feral cats.
Black-footed ferrets.
Badgers.
Minks?
Raccoons?
Peccaries?
Feral pigs?
It is my understanding that Eastern deer ticks usually only have one “meal” in their lifetime (several months), reproduce, and then die. (I suspect your local species of tick is similar.)
That reproduction, however, yeilds hundreds or thousands of offspring (kind of like a spider -> hundreds of little spiders).
So… it only takes a few “successful” ticks one season to populate the entire field next season.
And then there’s Duck’s list of critters also abiding in the field, mmmmmm… tick smorgasbord.
Out of those thousands of baby ticks and chiggers many end up not having a meal, but instead being a meal for birds.