Do spiders and ants have hearing?

No they do not have hearing as we know, but they have developed censorial organs which detect a wider spectrum of ultrasonic waves which we lack of, that is the reason they can walk and hunt in the darkness of the nigh with such precision, the barbs and celiums surrounding the head and the front of the theyr pincers are the sensitive organs to capture vibrations.

I am not sure about spiders but ants use sound to communicate. They even have a call for when they get buried and need help getting out. A man in the UK discovered this by making recordings, He keeps ant colonies in his basement for this purpose and has invented several devices to pick up the faint noises.