A crisp shirt may be one reason to use spray starch when ironing your clothing, but it also can be a tasty treat for insects like silverfish. The reality is spray starch is a food source for pests; when you use spray starch on fabrics, it attracts bugs. Over time, these insects will nibble away at your clothes and leave tears, holes and damage. If you must use starch, keep your clothing in airtight containers -- or give it up altogether. Modern irons can freshen, remove wrinkles and give crisp lines using just water and heat.