Trematodes live inside snails in moist environments. They glide
up the snails' antennae and start to blink. That is how they cause
the host animal to climb up a reed where a little light show takes place.
A bird is drawn to the light and it swallows the snail.
The trematode has now found its home inside the bird,
where it wanted to end up!

Translation: Johannes Göransson