Why do cacti have spines?
Cacti have spines, also known as cactus bites, for several reasons:

Protection:
- The main purpose of cactus spines is to protect the plant from predators such as animals looking to eat or damage the plant. The sharp spines act as a deterrent to prevent animals from coming too close.

Water conservation:
- Cacti are native to arid regions where water is scarce. The spines help reduce water loss by providing shade and creating a microclimate around the plant, reducing evaporation.

Temperature regulation:
- The spines of cacti also help regulate the temperature of the plant by creating a barrier between the plant and the harsh sun. This helps prevent the plant from overheating in the hot desert climate.

Defense mechanism:
- In addition to protection from predators, cactus spines can also serve as a defense mechanism against other plants competing for resources. The spines can help create a buffer zone around the cactus, preventing other plants from encroaching on its territory.

Assist in reproduction:
- Some cacti rely on their spines to assist in reproduction. For example, the spines of the cholla cactus serve as hooks to attach to passing animals, helping to disperse the cactus seeds to new locations.
In conclusion, cacti have spines, or cactus bites, for a variety of reasons including protection, water conservation, temperature regulation, defense, and reproduction. These spines play a crucial role in the survival and adaptation of cacti to their harsh desert environments.