The milk-drinking statues of Hindu temples are most probably acting like the Roman Catholic Church's "weeping Madonnas" but in reverse.
The most likely explanation is that the milk is being absorbed by capillary attraction - the movement of water through sponge-like material - just as Madonnas weep because water seeps out through scratches in the surface glazing.
According to Dr Julia Higgins, Professor of Polymer Chemistry at Imperial College, London, if statues are made of baked clay then they will absorb water (or milk) prodigiously: "Break a flowerpot, dip it in water and the water disappears like mad," she said. Especially after the weather has been hot and dry for a long period.
Last month, Dr Luigi Garlaschelli, a chemist from the University of Pavia in Italy, demonstrated that he could make his own "weeping madonna" from a glazed plaster statuette. As long as its impermeable glaze remained intact, the statue behaved normally. However, barely perceptible scratches in the glazing over the eyes produced droplets of water, like tears.
Professor Higgins stressed she did not wish to offend religious believers, but said: "There could be natural explanations depending on what material the statues are made of."
The same behaviour from marble statues "would be interesting", she said, "but I haven't done experiments". She concluded: "I'd be adamant that brass wouldn't do it."