You can place the spikes on opaque cubes or glass. Providing redstone power to a spike will force the spike to retract rendering it harmless. It will also retract all other spikes around it in a 3×3 depending on its orientation.
How to install Spikes Mod:
- Download and install Minecraft Forge.
- Download and install Grim3212 Core
- Download the mod.
- Go to %appdata%.
- Go to .minecraft/mods folder.
- Drag and drop the downloaded jar (zip) file into it.
- If one does not exist you can create one.
- Enjoy the mod.