It does get eaten.
By humans and camels and such...
But normal animals don't because they have little pointy things that jab your face.
It hurts a lot!
Broad leaves
Thorns, spines
no
in the body of a catus, water is stored as not much rain falls where a cactus so water is stored to prevent the cactus from dying out. there are thorns on cacti to prevent it from being eaten by a predator.
dont think they can protect themselves
Cactus
Many types of cactus are edible and commonly eaten by people. Prickly pear cactus is one example.
They have thick walls to keep water in. They have lots of roots to suck up whatever water there is. They have thin spines to protect themselves from being eaten. They have no leaves that might release water. They have pulpy centers to hold water in.
sting its prey
yes
by camouflaging
Yes, the part of the cactus that's eaten dies. But no, what's left of the cactus plant doesn't die necessarily. It depends upon the size of the piece that's eaten, the manner in which the piece is removed, and the condition of the remaining body parts.