What's a good, natural insect spray for babies?

I learnt back in school during camping trips that lemon grass is a good mosquito (and I'm guessing other bugs) repellent. We used to bruise the lemongrass stalk and dab the juice of the lemongrass on our pillows and blankets. And it worked well all the time. I haven't tried it recently but maybe I would since mosquitoes seem to be and huge issue these days. Also, I know that pandan juice keeps roaches away -- learnt this from a taxi uncle. He has pandan leaves in his taxi for the fragrance and also for keeping bugs out.