Here's why:

* Structure: Wood is made up of organic compounds that don't readily allow electrons to flow through them.

* Resistance: Wood has a high electrical resistance, meaning it opposes the flow of electricity.

* Practical Application: This is why wood is used in electrical applications where insulation is needed, such as in electrical poles, framing for buildings, and even some parts of electrical equipment.

However, it's important to remember:

* Moisture: Wet wood becomes a better conductor. Water is a good conductor of electricity.

* Types of wood: Some woods, like ebony, are slightly more conductive than others due to their composition.

So while wood is generally an insulator, its conductivity can be affected by factors like moisture and the specific type of wood.