From an early age, Dahmer manifested an interest in animals. Friends later recalled Dahmer initially collected large insects, dragonflies and butterflies which he placed inside jars. Later, Dahmer—occasionally accompanied by one or more of his few friends—would collect animal carcasses from the roadside; these animals Dahmer would dismember either at home or in an expanse of woodland behind the family home. According to one friend, Dahmer would dismember these animals and store the parts in jars in the family's wooden toolshed, always explaining that he was curious as to how each animal "fitted together."[13] In one instance, he is known to have impaled a dog's head upon a stake behind his house.[14]
Dahmer's fascination with dead animals might have begun when, at the age of four, he noted his father removing animal bones from beneath the family home. According to Lionel Dahmer, his son was "oddly thrilled" by the sound the bones made.[15]
...In 1968, the family relocated to Bath, Ohio. Two years later, over a family meal of chicken, Dahmer asked his father what would happen if the bones of the chicken were to be placed in bleach.[19] Lionel Dahmer was by this stage concerned as to his elder son's placid and lethargic attitude and his solitary existence; he was delighted at the initiative displayed by his son towards what he believed to be scientific curiosity;[19] therefore he willingly demonstrated how to bleach and, later, preserve animal bones. The knowledge regarding cleansing and preserving of these bones Dahmer would later utilize upon many of the animal remains which he continued to avidly collect and of which his father, being a chemist, taught his son safe usage.[20]
...In January 1979,[47] upon his father's urging, Dahmer enlisted in the U.S. Army,[48] where he trained as a medical specialist at Fort Sam Houston before, on July 13, 1979, being deployed to Baumholder in West Germany where he served as a combat medic. According to published reports, in Dahmer's first year of service, he was an "average or slightly above average" soldier.[49][50] However, due to his alcohol abuse, his performance deteriorated and in March 1981 he was deemed unsuitable for military service and later formally discharged from the army,[51] albeit honorably.[52]