Tiny bead-like radio transmitters were implanted into frogs. They were put into body cavities of frogs and even toads. Oddly, the small devices disappeared. The beads moved along the body into the bladder where they were, in due course, fully expelled from the body.
This may sound like something quite obvious and unremarkable until one is informed that the beads were two centimeters long and some of the frogs were only eight centimeters long. It is no mean feat for such a small animal. It was discovered that tissue from the bladder grows out and envelopes the foreign object. The object is then drawn into the bladder.
Apparently, frogs have evolved this to rid their bodies of the sharp extremities and extrusions of insects, their main diet. Furthermore, frogs have thin skin and they hop, landing clumsily. Thus, thorns from plants can easily pierce their bodies.
Researchers had assumed that when a transmitter was no longer mobile, the host animal was dead. Now they will have to find out if the transmitter was naturally expelled.
Economics by Ty Buchanan