Firefly

The game rolls a spawn rate for them at dusk and holds it until the next evening, so an empty night is not you looking in the wrong place. Reloading the world rolls a fresh number, which is the fastest fix when you need a lot of them and tonight is a dry one. New moons are the reliably good nights.

At a high resolution they are a single blinking pixel and easy to miss entirely against a dark treeline. Stand somewhere with a clean horizon behind you, or turn the brightness up. Once you know the flicker they are obvious, but nobody finds their first one by accident.

Bait, mostly, and it is respectable bait for how early you can get it. Bottled, they make a light source you can hang anywhere, which is why most people end up with a shelf of them. If you want a permanent supply without waiting on the weather, the statue version lights a room just as well even though the net will not take those.