Defender td5 Brown Relay

I stopped me landy today to speak to someone and kept hearing a click click noise. It got worse so I took cover of the fuse box and felt along and found the brown one clicking away quite happily. Took keys out and it didn’t stop. Started it and checked everything and all was well. Pulled the relay and started it up and checked everything and all was still good. So I goooogled it and it said it was the alarm sounder relay. I don’t have an alarm but wondered if it was for the 10as immobiliser thingy.
When my ecu died recently I got a replacement with the immobiliser removed so I assume that’s why it didn’t affect anything. Just quite glad that it didn’t start buggering about in the middle of the night.