A very interesting new BBC documentary, it's about domestic species but the style is the same as you would expect from a series about wild animals. BBC iPlayer - Pets - Wild at Heart - 1. Playful Creatures
It had its moments but, personally, I expect better from the Beeb. The recent nature output seems to be gradually becoming more and more dumbed down. Case in point, "Snow Babies" which broadcast over Xmas (godawful title, narration and script). To coincide with Valentines Day, they're broadcasting something called "Animals in Love." Suffice to say I won't be watching!
If you want an alternative program to watch on Valentine's Day, I recommend the PBS miniseries "Sex in the Wild".