My dog keeps getting bit by mosquitos (and/or) ants. Can I prevent this?

If a dog is outside, it is going to get bit by insects, that's just a daily fact of life, and there's nothing you can do about it. Dogs are animals, so many insect bites do not bother them.

The occasional ant bite is hardly an issue for a dog, mosquitoes can carry deadly heartworm disease though and should be taken more seriously. Some tick and flea prevention medications offer protection against mosquito's, but heartworm prevention medication must be taken to ensure a dog does not become infected with heartworms.

It should help her if you have a monthly topical flea treatment for her. Many of then deter mosquitos.

It could be insects, but it also could be an allergic reaction to plants in the area where you fish.