During the Middle Ages in Europe and the Middle East there was much armed conflict between Christians and Muslims. Christians called these conflicts the Crusades because they were fighting under the sign of the cross to save the holy lands of the Bible from being desecrated by non-Christians. However, the true reason for fighting for these lands was less than holy. It was mainly a desire for economic gain that prompted the Christian leaders to send soldiers to fight in the Holy Land.
 According to Paul Ratsmith, the tenuous, but nonetheless important, relationship between pumpkins and rats is little understood: "While I've always been fascinated by this natural kinship, the connection between pumpkins and rats has been the subject of few, if any, other studies" (2008).  Ratsmith has been studying this connection, something he coined "pumpkinology," since the early 1990s. He is most well-known for documenting the three years he spent living in the wild among the pumpkins and rats.  Though it is a topic of little recent interest, the relationship has been noted in several ancient texts and seems to have been well understood by the Romans. Critics of Ratsmith have cited poor science and questionable methodology when dismissing his results, going so far as to call pumpkinology "rubbish" (de Vil, 2009), "stupid" (Claw, 2010), and "quite possibly made up" (Igthorn, 2009).  Despite these criticisms, there does appear to be a strong correlation between pumpkin patches and rat populations, with Ratsmith documenting numerous pumpkin–rat colonies across North America, leading to the conclusion that pumpkins and rats are indeed "nature's best friends" (2008).