we have android phones and want to track our bicycles between flights like several people have done.  Any suggestions?

Rachael when I was shopping at an electronics store for AirTags, I asked about other options. They recommended a product called TILE. They work with either Android or Apple phones via an App. 

https://www.tile.com/en-au

We have Android phones also and put Tiles on our bikes and on our checked bag. It works just fine, as long as it can piggyback onto other Android phones,with the Tile app installed, in the nearby vicinity. The Tile network is extensive, but nothing as big as Apple. Still, it is better than nothing and probably worth giving it a try.

Your post reminded me to find the Tiles that we put on our bikes last year. I couldn't remember where I hid mine on the bike so I used the Tile app to make it ring and found it in the handlebar bag. 

I read that the batteries last about a year and sure enough the app tells me they're low. I'll have to plug that hole before we leave Thursday. It's comforting to be able to track the bikes after we check them in for the flight.

I already have one for Scott’s wallet so I’m going to put it in one of the suitcases.

I’m glad my post reminded you to find them!

Do Android phones have the equivalent of the FindMyPhone App/Function which is standard on iPhones and iPads? And can Android devices ‘detect’ each other if they belong to the same account?

If so, then another tracking/tagging  option for luggage & bikes is to use another phone as a ‘tag’. 

I have an old iPhone (unlocked with no SIM nor service provider, but it is visible on my Apple account) which can be detected by the FindMyPhone app on my active iPhone and my mini-iPad. The old iPhone phone, even if it is switched off, is detectable by the FindMyPhone app.  So is my mini-iPad.

Hence the three devices can track each other, or any of the AirTags. 

That's a good use for an old phone!

Graham, how long does the iPhone work in that mode before it runs out of power?  I understand that it’s powered off - just wondering how long it takes a powered-off phone to drain the battery.

I’m amazed that AirTags will run for a year on those little batteries.

Unfortunately,  there is no find my phone function with  Android, so the only option is to get some TILES. Using old iPhones as trackers sounds like a great idea, but only if you are an Apple user.