If they are sufficiently determined, they will take a lot of stopping.
A friend and I spent a lot of time putting in security at his son's business. HEAVY steel beam across door, can only be raised by electric hoist (disabled when Burglar alarm is enabled) brackets welded to beam to prevent doors being opened when beam is down, secure padlock under cover (to prevent tampering).
What did they do? Got in by wrenching d the back door and its frame OUT OF THE WALL, and then used the oxy acetylene to cut through the main door security, before stealling everything of value and a trailer in which to transport it.
My little workshop has no windows, and is double skinned and insulated, ( it would take a lot of time to find aw way through all the junk under and on the steel benches) and the door (a fire door) has a 6 lever lock supplemented by hinge bolts, although the hinge pins are pretty inaccessible.
Still, they could tunnel underneath and cut through the floor.
And this after climbing a 2 metre gate or a six foot high fence.
Maybe a few tame cobras would make a good defence? But then I'd be keeping a dangerous animal, and infringing the human rights of a criminal going about his work.
In my ideal world, a thief injured during a burglary would be told "You have only yourself to blame. If you had been acting legally, this would not have happened"
At least the chap who was permanently injured, whilst committing a burglary, had his claim for compensation dismissed.
As a pillar of the community, he had taken along a sixteen year old, "to keep him out of trouble". He is in no trouble now, having been shot dead!
For a little light relief:
An elderly widow neighbour left her house keys in the front door. They vanished before she could retrieve them. To the amusement of the local PC, as a temporary expedient I swopped her front door eurolock for my slightly shorter backdoor eurolock, until I could fit a new one for her.
The following night someone kicked her front door; presumably in frustration!
A former colleague fitted a trip wire connected to a 12 bore blank cartridge firer, across his garage doorway. Noisy, (a good alarm), and frightening for the crim, but basically fairly harmless.
Basically, as already said, don't advertise what is there, and just make entry very difficult. Hopefully, they will give up and head for somewhere less secure.
Howard