Additional thoughts and glad to see a few like the idea.
1. Listing a bug as missing after it completes its mission and returns home has a feeling that the bug is missing and lost. I like the missing status for bugs that are truly missing. Therefore, I interpret missing as lost in the wild, no one knows where they are and hopefully cachers will be on the look out for them.
2. Showing a bug with a status of retirement basically means the bug has completed his mission and has returned home safe and sound and out of circulation. The last cache could be the end-point but not list the bug in the inventory of the cache where it was pulled out of for retirement. Therefore the bug could still have its history.
3. As with my previous note, - just as in professional sports and in business, not uncommon that someone comes out of retirement. Therefore, the bug could go back into circulation with a new mission. Since it is probable the bug will be placed in a cache other than where it retired from, the system would need to keep the old travel history as well as the new. Two ways to address mileage: 1) just have it continue as technically speaking it did travel the distance between where it went into retirment and where it came out of retirmement or 2) don't count the mileage between the cache it retired from and the cache that it ended up in when it comes out of retirement.
4. Lastly - when a bug goes into retirement, it should still be listed in the inventory just in case you want to take it out of retirement. However - it should not be included in the list box of bugs when you log a find to a cache. Reason: if you have a bunch of bugs that are retired, the list could be rather large when the bugs are sitting on shelf in retirement status.
