How could young Larkin prevent bed bugs?

Small insects, in search of a place to live, found their way into bed ticks to eat the mattress stuffing and dead skin cells left behind by people. They annoyed anyone who used the mattress afterwards. Small children, like Larkin, would have been sent into the garden to find lavender, rosemary, mint, and bay leaves. These herbs freshened up the seldom-washed bedding and repelled insects from mattresses and ticks. If the Holland Pierpoint children were lucky enough to wake up in their own beds, they probably did so itching and scratching from bug bites.