I was on a escalator and noticed lights underneath the step. Why are they there ?
To help people step on or off the tread and not trip.
So the hamsters can see and walk in a straight line.
When I was a very young kid, (a long, long time ago) escalators creeped me out. I was afraid that it would somehow snag my toes as it disappeared under the floor at the top or bottom of the escalator, drag me through those little gear like spaces where the steps mesh with the floor plates and spit out a ME sized pile of ground meat on the other side. All these years later, I still have a habit of keeping my feet well clear of that space and stepping over the floor plate when I get off. RD is right, the light under the escalator helps me judge where the riser on the step is and keep my feet clear of the joint. Better safe than sorry, eh?