It has been proposed that Aztec human sacrifice and cannibalism can best be explained as a response to population pressure and famine. The greatest amount of cannibalism, however, coincided with times of harvest, not with periods of scarcity, and is better explained as a thanksgiving. Tenochtitlan received large quantities of food tribute and engaged in intensive (chinampa) agriculture. These two sources alone would have provided enough to feed practically the entire population of the city. The Aztecs also consumed various animals and insects that were good protein sources. The amount of protein available from human sacrifice would not have made a significant contribution to the diet. Cannibalism was not motivated by starvation but by a belief that this was a way to commune with the gods.