[header] How to catch and raise monarch caterpillars [title] Do some research. [step] Before you go out and find your little friend, it's very important that you go online and do some basic research on caterpillars and monarchs specifically. The more knowledgeable you are, the better care you will provide for your new friend. 
Do some research on basic anatomy and common diseases among caterpillars and butterflies. This way, you know what to look for if your new friend gets sick.