 Why are there only 11 men on the planet's surface?
The robots were built to serve Man; to do his work, see to his comforts, make smooth his way. At midday some few of the blue sun's rays filtered through to the jungle floor, but now, late afternoon on the planet, the shadows were long and gloomy. Then, through the trees he saw the clearing of the camp site, the temporary home for the scout ship and the eleven men who, with Alan, were the only humans on the jungle planet, Waiamea. The planet's double moon had risen and he could see a robot rolling slowly across the clearing in his general direction, blasting indiscriminately at whatever mind impulses came within its pickup range, birds, insects, anything.
 They served as a lookahead team for a larger group.
 They wanted to establish a colony only for men.  They served as a lookahead team for a larger group.  They wanted to go unnoticed as they set up on the planet's surface.  There was not enough space on the ship for more people.