As others have said already, yes you can hook them up to a light switch.
As a matter of fact, most manufactures specify that you do just that. Hooked to a light switch, you can either have the light function as a motion sensor light, or you can have it function as a regular On/Off light. Attaching it to a switched circuit gives you the option to do both.
Having it hooked directly up to a non-switched circuit will only give you ability to have it function as a motion sensor.
Jim