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!
They eat cactus because cactus has water in it.
it has thorns and it is very bitter
Thorns, spines
Broad leaves
dont think they can protect themselves
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.
no
camels for starters...
yes
sting its prey
by camouflaging
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.
Cactus
Many types of cactus are edible and commonly eaten by people. Prickly pear cactus is one example.