The cows had younger calves who had started sucking milk from their mothers, and some of the cows had newly given birth, but now, because of love, the cows enthusiastically showed their affection for the older calves, which had left off milking. These calves were grown up, but still the mothers wanted to feed them. Therefore Balarama was a little surprised, and He wanted to inquire from Krishna about the reason for their behavior. The mothers were actually more anxious to feed the older calves, although the new calves were present, because the older calves were expansions of Krishna. These surprising events were taking place by the manipulation of yogamaya. There are two mayas working under the direction of Krishna -- mahamaya, the energy of the material world, and yogamaya, the energy of the spiritual world. These uncommon events were taking place because of the influence of yogamaya. From the very day on which Brahma stole the calves and boys, yogamaya acted in such a way that the residents of Vrindavana, including even Lord Balarama, could not understand how yogamaya was working and causing such uncommon things to happen. But as yogamaya gradually acted, Balarama in particular was able to understand what was happening, and therefore He inquired from Krishna.