Mice tend to investigate new objects in their home range. Rats, especially Roof Rats, are suspicious of objects that suddenly appear in their midst. Roof Rats are Neo-Phobic (afraid of new things). Norway Rats and Roof Rats typically ignore Rat Poison and Rat Traps for 3-5 days or even weeks, especially if other food continues to be routinely available to them. Many Roof Rats will not consume a food source even when placed in its regularly travelled path unless it smells another rat’s breathe on the food source.