Damselflies are small members of the order Odonata, first cousins of the dragonflies, who are also Odonata (which means 'toothed jaw'). Damselflies are finer and less robust than their kin and their flight muscles are less developed, allowing them to rest with their wings folded neatly above their bodies. Approximately a third to a half the Odonatae are damselflies, or the sub-order Zygoptera (meaning 'paired wings'). There are currently about 25 species that can be seen around Preuilly-sur-Claise; compared to about 20 species in the whole of Britain; 30 in the whole of France and at least 100 species in Australia.
Finally, enjoy this offering from French animators, Miniscule TV. It is a shame that it has been over compressed so the quality is rather poor, but amusing nonetheless. If you liked it, you can find several more of their little vids on YouTube.
*Water having such a high level of dissolved organic nutrients that it is more or less devoid of oxygen. A particular problem of water bodies in agricultural areas because of fertilizer runoff (both artificial and natural).
[Note: this post has been edited to correct my misidentification of the Small Redeye.]