I hate to say this, but...any dummy can learn to pick a lock. This means that the locks on your house's doors are probably very "pickable" unless you have a top-flight lock system-which few homes actually have.
An article on lifehacker.com describes how easy it was for the writer to pick a lock from a lockpick set. He discovered that this type of lock isn't much different than door locks. He also makes a point about the term "pick resistant." This doesn't mean "pick preventable."
Don't count on your average door locks to be pick resistant. They are pick easy. Grade 1 locks are the most pick resistant, while Grade 3 are easy.
The article also notes that a fancy looking lock might entice a thief to try to pick it, as he'll assume a fancy lock means lots of valuables inside. A Grade 1 deadbolt doesn't have to look snazzy, though.
The author also writes that there are other ways than picking to get past a lock.
Many burglars use non-picking methods. The bottom line is that average locks are just plain weak. But not all intruders care to buff up their lock picking skills. Impulsive intruders, such as teen boys, just want to get in without being savvy about it, so they'll often kick open a door, smash through a window or ring the doorbell till someone answers and force their way in. Heck, they may even do what so often they do: waltz through an unlocked door.
The FBI says that most burglars get in via forced entry. But it greatly helps to have great door locks. Intruders don't want to get noticed. They don't want to set off every dog within a hundred yards barking. They usually really care about being as sneaky as possible. But if they lack lock picking skills, they'll likely give up on a well-protected house.