Step 1: Understanding neuroglia.
Neuroglial cells support, protect, and nourish neurons in the nervous system.
Step 2: Functions of neuroglia.
They provide nourishment, help in regeneration, and some perform phagocytosis.
Step 3: Key difference from neurons.
Neuroglial cells do not conduct nerve impulses and hence are not excitable.
Step 4: Conclusion.
Therefore, excitability is NOT a characteristic of neuroglial cells.