Oulens-sous-Échallens is a municipality in the district of Gros-de-Vaud in the canton of Vaud in Switzerland. History Oulens-sous-Échallens is first mentioned in 1207 as Ollens. Geography Oulens-sous-Échallens has an area, , of . Of this area, or 64.5% is used for agricultural purposes, while or 24.7% is forested. Of the rest of the land, or 10.9% is settled (buildings or roads). Of the built-up area, housing and buildings make up 2.9% and transportation infrastructure make up 6.3%. Power and water infrastructure as well as other special developed areas make up 1.4% of the area. Out of the forested land, all of the forested land area is covered with heavy forests. Of the agricultural land, 57.2% is used for growing crops and 6.0% is pastures, while 1.4% is used for orchards or vine crops. The municipality was part of the Échallens District until it was dissolved on 31 August 2006, and Oulens-sous-Échallens became part of the new district of Gros-de-Vaud. Coat of arms The blazon of the municipal coat of arms is Or, fretty Sable. Demographics Oulens-sous-Échallens has a population () of . , 8.1% of the population are resident foreign nationals. Over the last 10 years (1999–2009) the population has changed at a rate of 11.7%. It has changed at a rate of 12.4% due to migration and at a rate of -0.2% due to births and deaths. Most of the population () speaks French (403 or 94.4%), with German being second most common (16 or 3.7%) and English being third (3 or 0.7%). There are 2 people who speak Italian. Of the population in the municipality 127 or about 29.7% were born in Oulens-sous-Échallens and lived there in 2000. There were 178 or 41.7% who were born in the same canton, while 73 or 17.1% were born somewhere else in Switzerland, and 38 or 8.9% were born outside of Switzerland. In there were 3 live births to Swiss citizens and were 3 deaths of Swiss citizens. Ignoring immigration and emigration, the population of Swiss citizens remained the same while the foreign population remained the same. There was 1 Swiss woman who emigrated from Switzerland. At the same time, there was 1 non-Swiss man who immigrated from another country to Switzerland and 2 non-Swiss women who emigrated from Switzerland to another country. The total Swiss population change in 2008 (from all sources, including moves across municipal borders) was an increase