In "The Sims 3" you sometimes get a glitch in the game that freezes one or more of your Sim characters in a household. This can be frustrating because it often only affects one Sim and the rest in the household move around as normal. However, a cheat will reset the Sim and unfreeze him.
Open the cheat window in the house with the frozen Sim.
Type "resetsim (first name) (last name)" in the cheat box, where "(first name)" and "(last name)" are the first and last name of your Sim. Hit "Enter" to activate the cheat.
Watch your Sim unfreeze.
You will need to perform this cheat for each frozen Sim individually.