A beetle nursery!

In what was a discarded pear core, a nursery of orange-reded beetles has been created. I missed taking this photo last week, and when I returned with my camera the following day, there was not a little dot of orange anywhere to be seen. Perhaps it was exercise time, for there was a full compliment again.
I am not sure what they are called, but the adults seem to be permanently joined at the abdomen ( I am not sure of the correct term.)