I thought, and I am almost sure that deadlocks are fitted as standard....well they are on mine. The deadlocks are activated by the remote control when you set the alarm. When you press the arm button you will hear an initial "clonk", ie door lock operating. Just after 1 flash or 2 of the indicators, you should hear a second "clonk", ie the deadlocks engaging.
Initially, I thought my car was unlocking on the second "clonk", but after talking to the techy guy at Honda, he pointed out that it was the deadlocks.

If you only use the "non-alarm" remote, if you still have it, you will only hear one "clonk".
Pressing the close button twice might activate the deadlocks....just guessing on this one!!

Not sure if the word "clonk" best describes the noise, but it was the only one I could think of.