I was amazed at how many times the cats seem to stop moving. You think something is wrong but they are just resting or getting ready to molt.
It seems like it is watching a pot of water boil. Seems to take longer when you watch.
They seem to hang in J between 12 and 24 hours.
Temperature, etc can affect how fast this happens.
Sometimes I'll get up in morning or come back from work and they have PUPA'd.
Right before they turn into chrysalis, the filaments (antennas) will droop.
If you aren't watching at the right time, poof the cat will be gone and a chrysalis is left.
I've been lucky to see the process "live" a few times.
On Youtube there are some videos of the process.
Seems like it just 15 seconds or so for the process to occur and then they keep winging for a little while til the chyrsalis hardens.
Saving one egg, cat and butterfly at a time