$ 0 0 If it works with 1 LED, maybe there isn't enough current to supply many LEDs. I'm not a electronics guy, so only guessing. https://www.google.com.au/search?q=dark+activated+switch&client=opera&hs=GF1&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjrh5Os9YXQAhWEVZQKHUtWBRIQsAQIHA#tbm=isch&q=dark+activated+led