Tick repelent + bravecto

Hi,

My dogs have been on bravecto and I will still be giving it to them.

From time to time, specially in spring they still come home with ticks and I want to know if there's a natural repelent that I can add into the routine that can help keeping ticks away. I don't want to mix collars with repelents as I was told a few years back that the collars also have chemicals and that along with the bravecto might not be the best.

We also have a baby in the family and don't want any topical chemicals on the dogs skin/fur.

Any advice?

Thanks