Fifteen years ago, Randy Geissler placed a computer chip in his father's hand. Encased in a tiny glass tube, it wasn't much bigger than a grain of rice. Geissler's father, a dairy farmer from Wisconsin, stared incredulously. “What are you going to do with that?”

A decade later, Geissler says he often answers a different question: "What can't you do with that?"

Today those chips, developed by Digital Angel Corp. in St Paul, are implanted in more than 30 million pets, livestock and fish worldwide, providing instant electronic identification. The chip, marketed as LifeChip in Australia (Indexel in Europe, IdentiChip in the UK and HomeAgain in the US) has reunited thousands of lost pets with their owners and can also be used by farmers to track livestock. National Parks buy it to monitor all forms of wildlife.

Now Digital Angel is poised to take the next step, chips that will not only identify an animal but begin to tell how it feels.

Last year Destron Technologies, won approval from US government regulators to market the Bio-Thermo microchip, which gauges an animal's body temperature. The company plans future biosensor chips that track other important parameters for an animals well being.

The Bio-Thermo chip works the same way as a regular chip except it transmits more information. The device will mean that veterinarians won't have to wrestle with scared animals while using a tempanic or rectal thermometer. The latest Destron scanners are software upgradeable to read the new Destron research based products as they become available.

Destron Technologies began in 1945 as Fearing Manufacturing, a St Paul-based company that made plastic ear tags for livestock. In 1993, Fearing bought Destron IDI, a struggling Boulder Colorado company doing research and manufacturing on microchips.

Destron Technologies is today an important part of Digital Angel Corporation, a high tech multi discipline company that specialises in implantable and external electronic identifi cation systems for animals.