Merry Christmas! These lights are modified versions of Creatures Labs' old Yule Pack. Unlike the originals, this version works in both C3 and DS. They also have a few colors to choose from, and even different patterns like solid and chaser lights. Simply click on them to turn them on or off. Shift-clicking changes their color and also turns them off. Slightly annoying, but otherwise the color wouldn't update properly.
They can also be connected to each other and other connectable agents, like the ones from C3. Click near the last light on each end to find the input/output ports. String a few lights together and add some form of input, like the pulse switch from C3, and they even blink one after another. There's even a pulse switch for DS here, under the DS connective agents pack, though it requires C3 installed to work.
Also the chaser lights are slower then the other two lights. So they might slow down the other ones if connected to them. They're designed to work with other chaser lights, and work well together.