Both spikes and loose nets can be installed over nest sites to prevent the bird from returning, but nets are not a humane option since birds and other wildlife can get tangled in them. 

Spikes are a humane alternative that deter nesting without harming the birds. In small areas, like vents, a very fine mesh net can be installed to prevent the bird from returning. These nets don't generally pose a risk to the birds.

You can take multiple approaches to keep animals out of your edible landscape. You can use natural repellents such as mint and cayenne pepper to deter them from your garden. You can also build a fence (or opt for a privet hedge) or keep the most enticing plants in a sectioned-off area. The most efficient method of keeping your four-legged guests at bay is to determine what animal it is and create a customized plan for them. 

Popular nesting areas outside of a home include eaves, porches, gutters, and chimneys. However, some birds can make their way into your attic or ventilation systems. A reputable removal service will inspect your home's interior and exterior for any evidence of roosting and nesting birds while they prepare to remove them.

Identifying the specific animal running on your roof at night can be challenging without direct observation. Common nocturnal roof visitors include raccoons, squirrels, opossums, and rats. Raccoons are bigger and can create heavy thumping sounds. Squirrels are agile and may produce rapid scurrying noises. Opossums tend to move stealthily with less noise. Rats can make scratching or gnawing sounds. To determine the culprit, look for signs like footprints, droppings, or damaged areas near the roof. For accurate identification, consult a pest control professional or set up wildlife cameras near potential entry points.