Why is blenders hair system making spikes? I am using a hair/particle system but all of the hairs look like spikes not hair:



How can I set it so they all have a consistent thickness and how can I adjust the thickness?
The setting for hair particles in cycles are in Particles > Cycles Hair Rendering and Particles > Cycles Hair Settings.

To make the hairs a constant thickness, set the root and tip thickness settings to the same value and disable Close Tip:



To get a cylinder-like result, you will also have to disable Particles > Cycles Hair Rendering > Cull Back-faces so the backs of faces are not hidden:



See the manual for more information.