Garter snakes (Thamnophis spp.) are very common in urban gardens and residential areas in the spring time. These snakes are attracted to warm objects that give them the heat they need for digestion and growth. They actually prefer urban and suburban yards over farm locations.
The Garter snakes in Eastern Nebraska may be one of three types - Common, Plains, or Ribbon. All are extremely variable in color. While most have orange, yellow, and reddish stripes along the length of the body, some may be very dark or even cream-colored. In Nebraska, the rule of thumb is that any snake with a line running down its body length mid-center and/or on each side is one of our Garter snakes.
These snakes are usually 2 to 3 feet long when full grown. They will sun themselves in the day and hide at night. When approached, they will try to take cover. If attacked, the Garter snake will try to defend itself. They will not offensively attack any person or pet.
In early spring (April), Garter snakes mate in large groups, and then become more secretive in the hot dry portion of the summer. In late summer and fall, the female gives birth to 12 to 20 young. Most will not live to the next spring.
Garter snakes may frighten you, but are actually harmless. They feed on many insects, as well as worms and grubs. They are beneficial in gardens or flower beds as they control harmful insect populations. I believe that education to allay the public's fears, linked with habitat modification, are important to prevent snake populations from decreasing.
When a portion of garter snakes' home range is disturbed in such a way that vegetation is removed and cover habitat is destroyed, snakes are no longer seen in that area. If rock walls known to harbor large numbers of garter snakes are removed and replaced with solid cement structures, snakes migrate from that home range and may not be seen near that location for many years.
In my study, it was observed that unfamiliar locations where snakes were not previously sighted were more "sterile" looking, with less weedy vegetation and little cover. Rock or lumber walls that are tight fitting with few areas where snakes could find refuge may decrease snake numbers. Trimming plants, shrubs, and bushes, as well as removing branches low and close to the ground lessen the favorability of habitat. Also, removing debris and high vegetation may increase predation pressure on the snakes.