Don't know if it's been done before but post your little monsters on your bed. It was easy with Oliver as he spent most of the time on ours when we first got him. Here's some of Oliver and Chubchub. Betty doesn't bother with beds.
Juniper only snuggles on the bed in the dead of night, but my baby girl Gwen was a power napper at all hours. This is her "don't bother me! I'm napping" glare, probably in response to me getting out the vacuum cleaner.