Maybe their diet would shift but a lot of animals eat ticks. Frogs and toads, many smaller birds like warblers and probably house sparrows and robins, chickens love them, and of course opposums and mice.

Similar for mosquitos. I see the house sparrows around here catching mosquitos all the time. I’m pretty sure dragon flies feed heavily on them too.

Wow I haven’t read a good chunk of this list, and I thought I was a sci-fi book afficionado. Thanks for adding to my summer reading list! Might start with either Parable of the Sower or Never Let Me Go.