I mean we have thermal imaging cameras but still use blood hounds for search and rescue, as you pointed out dog sniffers at airports. pigeons while out of date nowadays can still be used as a means of transporting messages (my neighbour breeds carrier pigeons competitively) nevermind the affects that cows have had on historical farming. and horses can even be a common method of transportation.<br><br>Honestly what's really sad about this is that we're more surprised clams would be used for this purpose. had we gone back into 200 years ago it would have sounded like a perfectly normal or even brilliant idea.