A little something else I found that may be of use also:
Insect Repellent
Here is an easy repellent to make that has a shelf life of around six months. Label jars mosquito, tick, etc. for quick identification.
10 to 25 drops essential oil
2 tablespoons vegetable oil (olive oil is fine)
1...
I wonder if lavender and red thyme essential oil will work for them. I use both oils to repel mosquitoes from us, indoors and outdoors. I place a few drops on cotton balls and place them on head boards or night stands. If you are sensitive to oils you may want to use a carrier oil to blend...