Here is a sequence that was shot several seconds one from another. Thigmotropism is a term for plant parts moving in reaction to touch. Here I'm touching Opuntia filaments as a pollinating insect would do. Filaments start moving towards the flower stile in an attempt to put pollinator - insect in this case - in contact with flower's stigma, to capture pollen from other flower that this insect hopefully brought, and at the same time holding the insect tight, making sure it gets pollen from that flower on itself and transport it to the next flower it visits.
Many Opuntias and other Cacti as well show the same filaments motion on touch.
Opuntia compressa is a common plant of the US East coast, spreading from Florida to Massachusetts. It is cold hardy and can easily overwinter under snow.No matter how wet the soil is the plants will partially dehydrate in late fall, preparing to frosts, and will not plum up again until the warmth of the spring.