Caterpillars eating my broccoli!

Pesky critters raise their heads again! My lovely purple sprouting broccoli is about 2 foot tall now, and are growing well. I have to search each one by hand each day looking for small green caterpillars that like to hide in the very small leaves in the middle. They are a bit eaten all over the place - but still looking healthy. I left them for about 4 days without checking - bad mistake! Went out today after some hard rain and they were crawling all over the leaves in broad daylight. One solution - SQUISH!