Drugged or Chilled?

We have a nice patch of catmint in the corner of our garden. The cats love it. There is a little flattened section of it where they lie in comfort while they sniff away and get their fix. Amelia the Birman was out with me while I was gardening today. She spent quite a long time in the catmint and then lay in the shade looking either half-drugged or half-asleep.