Stanford professors have discovered that ants are so efficient at foraging, the way they determine how hard to look for food closely mirrors one of the main protocols underpinning the web. Had the discovery been made in the 1970s, it could have likely influenced the design of the internet, posited one of the researchers.
Harvester ants face a tricky optimization problem. Seeds can provide valuable water for the colony, but looking for food means expending water in the process. So for the colony, the ideal number of foragers to send out depends on how much food is available.
IF THE GROUP TAKES A LONG TIME TO COME BACK, THAT MEANS FOOD (BANDWIDTH) IS IN SHORT SUPPLY
Deborah Gordon and Balaji Prabhakar discovered that in order to solve this problem, the ants use the same message-acknowledgment framework found in the Transmission Control Protocol, better known as TCP. When using the protocol to transmit a file, the sender chops it into bite-sized packets; if and when the receiver gets a packet it sends an acknowledgment or “ack” back to the sender. A fast flow of acks implies there’s a lot of bandwidth, allowing the sender to pump up the transfer speed. And a slowdown in the flow of acks indicates there isn’t much bandwidth, so the sender can throttle the transfer accordingly. Gordon and Prabhakar found that in the ant world, when foragers return with food quickly the colony responds by sending more. And likewise, taking a long time to come back indicates that food is in short supply, and the colony will scale back the operation accordingly. The researchers jokingly refer to the behavior as the “anternet.”
Gordon, who has been researching ants for 20 years, thinks the insects still have a lot to show us about building efficient networks. “I think as we start understanding more about how species of ants regulate their behavior, we’ll find many more useful applications for network algorithms.”