Are burglars tele casing my place?

I get a lot of strange phone calls.  When I answer, all I get is silence.  So I hang up.  Are they calling to see if anyone is home?  So they can burglarize the place in safety?  Even though I have little in the place of worth to a burglar or a fence.  About the only worthwhile items are a seven year old Sony flat screen TV and a HP laptop.