Discovered: the new secret of mistletoe; it's actually the lack of thought that counts; why holiday shoppers are so rude; miracle at Christmas market.

Animals hang around the mistletoe. Lonely people in desperate need of a smooch aren't the only ones who hover near the mistletoe. Vertebrate animals in Australian forests also stick close to this parasitic plant, because it attracts edible insects to the forest floor. Researchers recently found that when mistletoe is removed from eucalyptus trees in such environments, up to a fifth of the creatures living in the area will leave. [Scientific American]

Don't put too much thought into gifts. "It's the thought that counts," right? Not empirically, say researchers. They found that going off gut feelings while last-minute shopping may work better than endlessly analyzing whether or not they'll like that item you're thinking about buying them. "If you're looking at those shiny new winter shovels for your spouse, ask yourself, 'Is this right or wrong?' and trust your gut. You'll be well served by your intuition," says Boston College's Michael G. Pratt about this research. "It's likely that your spouse doesn't want a shovel and you don't want to be the one who gives that gift." [Boston College]

The rage of the holiday shopper. When shoppers break social norms—cutting in line, or strewing clothes all over the ground, let's say—other shoppers seek to punish them, researchers from the University of British Columbia and University of Alberta find. But they've also seen that this inclination to punish rude shoppers can be mitigated. For instance, if shoppers themselves were just called out for bad behavior, they're likely to give others a pass. And if someone cuts in line because they claim to be late for an appointment, other shoppers are more likely to let them if they have higher social status. "Punishment is a complex decision for consumers to make as it is difficult to punish someone but also difficult to look the other way. Consumers do not seem to make these decisions lightly, and a number of interesting factors influence consumer punishment decisions," write researchers Lily Lin, Darren W. Dahl, and Jennifer J. Argo. [University of Chicago Press Journals

Fish get geomagnetism. It's a Christmas miracle in geomagnetic discoveries! After perusing the carp for sale in Czech Christmas markets, Hynek Burda of Prague's University of Life Sciences noticed that the fish kept aligning themselves along a north-south axis. After studying and photographing 14,000 fish from 25 different markets, he found that they all did the same thing. This suggests to Burda that the fish have an innate sensitivity to the Earth's geomagnetic forces. [PLoS]