Nested

The empty, spent seed heads of knapweed make ideal little nooks for a couple of 7-spot ladybirds to bunk up in. Today was so mild that they ventured out while the sun shone but returned later in the afternoon. 

Sometimes you find much much larger numbers of ladybirds overwintering in crannies or crevices. Why do they congregate like this?  My first thought was for warmth but then I realised that insects are cold blooded. In fact it's for a very specific form of protection. Ladybirds are aposematic, which means that their vivid coloration acts as a warning to potential predators that they are foul-tasting. Grouped together, it only needs the sacrifice of one ladybird to repulse an  incautious predator. The message that red is for danger will come across loud and clear and the rest of the dormitory will be spared.

More about this here.