Lack of Water

• Bugs often wander indoors during the hot, dry summer in search of water. This is why bugs are commonly found near kitchens and bathrooms. If the bugs cannot find a source of water, they eventually die. Sealing doors, windows, pipes, vents and exterior cracks are the only ways to keep bugs out, but you can ensure they die rather than thrive in your home by draining water sources like sinks and tubs and repairing leaks.
  
  

Lack of Food

• Bugs also come indoors in search of food. Like ants to a picnic, other pests make a beeline for garbage and food left out. Much like their need for water, bugs who cannot feed in the home eventually die. Removing the garbage daily or fastening a lid to the garbage can staves off the pests, as does storing food in airtight containers or the refrigerator.
  
  

Light Sources

• Flying insects are attracted to light sources like lamps for several reasons. Some, like bees, use the sun and moon to navigate, and cannot differentiate light sources. Others, like moths and flies, are attracted to the heat a lamp emits. Dead insects are sometimes found near lamps and porch lights because they either fly into the lamp and experience trauma, or they burn themselves on the hot bulb.
  
  

Poisoning

• Having your home inspected and sprayed regularly by a licensed exterminator is key to preventing bugs in the home and killing those that manage to invade. Many dead bugs have been killed by pesticides in the home. Spotting dead bugs does not necessarily mean that the exterminator is ineffective. The fact that the bugs have died is a sign the pesticides are doing their job.