These observations, based on experiments with radioactive sugar, are reported by Dr. Roland Ribbands of Cambridge University. In one of these experiments, Dr. Ribbands reports, “a marked bee is trained to collect sugar solution from a small glass tube, and when radioactive sugar is substituted the bee continues to collect the radioactive syrup quite happily. It returns to the hive and what happens to the labeled sugar can be followed quite easily. Every bee that receives some can be spotted by means of a Geiger counter. By collecting a sample of bees from the hive, one can discover what proportion of the colony has acquired some of the sugar. One stomachful can be shared among almost all the bees of a large colony. The experiments indicate that this sharing is a random affair. The sugar is passed on irrespective of the recipient’s age or occupation.” Building up of a colony odor through universal sharing of the food supply enables members of the colony to recognize each other. This apparently makes little difference when food is abundant but becomes of great importance in periods of scarcity. “At those times of the year,” Dr. Ribbands points out, “when there are insufficient flowers to provide all the bees with food, they often try to steal the honey stored in other colonies. Then the ability to recognize hive mates and to distinguish them from other honey bees will enable a colony to defend itself against attempts at robbery. “However, the honey bee community does not defend itself by attacking every invader that does not possess the community odor. Strangers are attacked only under certain circumstances. In order to investigate these circumstances two colonies of differently colored bees were placed close together, with their entrances only two inches apart, so that bees often went into the wrong colony by mistake. When good supplies of nectar were available, the intruders were allowed to enter the strange colony, but when nectar was short the strangers were attacked and thrown out, often being killed in the process. “Production of a common and distinctive odor which enables the colony to defend itself against members of other communities is a very important consequence of the habit of food-sharing. Better sharing means better defense and so a greater likelihood that the community will be able to survive and perpetuate its kind. The habit plays the key role in the system of communication which enables the new forager to learn about suitable crops, in that the new recruit always receives a sample of the crop the colony is working. The first flight becomes a search for a crop with a similar scent. The habit enables the worker bees in a colony to be apprised of the presence of their queen. A substance derived from her body is conveyed from bee to bee in the shared food, and in the event of any deficiency in the substance they take steps to rear another queen.