Unity skips when spawning Prefabs

Does anyone know why Unity skips a few frames when it loads certain prefabs? The Prefabs in question are models I made myself ranging from 189Kb to 245kb.

On first instantiation of prefabs it takes a moment to load those which can result in a little hiccup. One solution is to have those prefabs as part of the scene already (in some hidden place). That will likely make the scene loading take a little longer but that's usually less noticeable than the hiccup when loading the prefab.

Another possibility is splitting up the prefab in smaller parts or using smaller (less complex) models.

This is a bit of a stretch, and it requires Unity Pro, but you could stick your prefab in another, empty scene and load it with Application.LoadLevelAdditiveAsync. This shouldn't cause any lag at all.