on lettering: paulshawletterdesign.com.

New York City's architectural style: N. White, E. Willensky, and F. Leadon, AIA Guide to New York City (New York: Oxford University Press, 2010).

hunger to pursue visual stimuli that give us pleasure: I. Biederman and E. A. Vessel, "Perceptual Pleasure and the Brain," American Scientist 94 (2006): 249255.

pregnant ampersand: www.aiga.org/lettering-grows-in-brooklyn.

6-8 Delancey Street: J. Mendelsohn, The Lower East Side Remembered and Revisited: A History and Guide to a Legendary New York Neighborhood (New York: Columbia University Press, 2009).

"shoes for abnormal feet": Advertis.e.m.e.nt, Jewish Frontier, vol. 18, 1951, p. 43.

locally famous robbery: H. P. Jeffers, Commissioner Roosevelt: The Story of Theodore Roosevelt and the New York City Police, 18951897 (New York: Wiley, 1996).

"disorderly house": Report of the Special Committee of the a.s.sembly Appointed to Investigate the Public Offices and Departments of the City of New York and of the Counties Therein Included, vol. 2 (Albany, NY: James B. Lyon, 1900), p. 2002; and R. Zacks, Island of Vice: Theodore Roosevelt's Doomed Quest to Clean Up Sin-Loving New York (New York: Doubleday, 2012).

Tetris study: R. Stickgold, A. Malia, D. Maguire, et al., "Replaying the Game: Hypnagogic Images in Normals and Amnesics," Science 290 (2000): 350353.

INTO THE FOURTH DIMENSION.

"if you're ever bored or blue": M. Kalman, The Principles of Uncertainty (New York: Penguin, 2007).

"no two human Umwelten are the same": J. von Uexkll, "A Stroll Through the Worlds of Animals and Men," in C. H. Schiller, ed., Instinctive Behavior: The Development of a Modern Concept (New York: International Universities Press, 1934/1957), pp. 580.

"nude, shamed look": A. Kazin, A Walker in the City (New York: Harcourt Brace Jovanovich, 1951), p. 78.

personal s.p.a.ce: H. Hediger, Wild Animals in Captivity (London: b.u.t.terworth, 1950).

judgments about people: M. Bar, M. Neta, and H. Linz, "Very First Impressions," Emotion 6 (2006): 269278.

sclera and width-height ratio of eye: H. Kobayashi and S. Kohshima, "Unique Morphology of the Human Eye," Nature 387 (1997): 767768.

neurobiology of vision: N. J. Emery, "The Eyes Have It: The Neuroethology, Function and Evolution of Social Gaze," Neuroscience and Biobehavioral Reviews 24 (2000): 581604.

neuropsychology of attention: R. Datta and E. A. DeYoe, "I Know Where You Are Secretly Attending! The Topography of Human Visual Attention Revealed with fMRI," Vision Research 49 (2009): 10371044.

newborns babies' interest in gaze: T. Farroni, G. Csibra, F. Simion, and M. Johnson, "Eye Contact Detection in Humans from Birth," Proceedings of the National Academy of Sciences 99 (2002): 96029605.

eye contact and attachment: K. S. Robson, The Role of Eye-to-Eye Contact in Maternal-Infant Attachment," Journal of Child Psychology and Psychiatry 8 (1967): 1325; and A. J. Guastella, P. B. Mitch.e.l.l, and M. R. Dadds, "Oxytocin Increases Gaze to the Eye Region of Human Faces," Biological Psychiatry 63 (2008): 35.

eye contact generally: A. Senjua and M. H. Johnson, "The Eye Contact Effect: Mechanisms and Development," Trends in Cognitive Sciences 13 (2009): 127134.

eyes and art: M. F. Marmor and J. G. Ravin, The Artist's Eyes: Vision and the History of Art (New York: Abrams, 2009), pp. 125127.

never complains about waiting for the subway: G. K. Chesterton wrote something similar about boys in railroad stations in On Running After One's Hat.

canonical "creative brain": o. de Manzano, S. Cervenka, A. Karabanov, et al., "Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals," PLoS One 55 (2010): e10670.

streetlights: "Lighting," NYC Department of Transportation Street Design Manual, 2010. http://www.nyc.gov/html/dot/html/about/streetdesignmanual.shtml.

FLIPPING THINGS OVER.

categories of insect sign: C. Eiseman and N. Charney, Tracks and Sign of Insects and Other Invertebrates: A Guide to North American Species (Mechanicsburg, PA: Stackpole Books, 2010).

"people stood overwhelmed with awe": Quote from the Wabash Plain Dealer in D. E. Nye, Electrifying America: Social Meanings of a New Technology, 18801940 (Cambridge, MA: MIT Press, 1992), p. 3.

on invertebrate attraction to lights: C. Bruce-White and M. Shardlow, "A Review of the Impact of Artificial Light on Invertebrates," (2011), retrieved from http://www.buglife.org.uk/.

ants in the medians: www.livescience.com/11068-ant-oases-nyc-street-medians.html.

search images: S. J. Shettleworth, Cognition, Evolution, and Behavior (New York: Oxford University Press, 1998).

blue jays trained to look for camouflaged moths: J. Alc.o.c.k, Animal Behavior, 9th ed. (Sunderland, MA: Sinauer, 2011).

olfactory search images: V. O. Nams, "Olfactory Search Images in Striped Skunks," Behaviour 119 (1991): 267284; F. R. Cross and R. R. Jackson, "Olfactory Search-Image Use by a Mosquito-Eating Predator," Proceedings of the Royal Society B 22 (2010): 31733178; and I. Gazit, A. Goldblatt, and J. Terkel, "Formation of an Olfactory Search Image for Explosives Odours in Sniffer Dogs," Ethology 111 (2005): 669680.

Sacks' first Tourette's patient: http://blog.ted.com/2009/09/qa_with_oliver.php.

the "clay pitcher search image": J. von Uexkll, "A Stroll Through the Worlds of Animals and Men," in C. H. Schiller, ed., Instinctive Behavior: The Development of a Modern Concept (New York: International Universities Press, 1934/1957).

visual search in the brain: M. P. Eckstein, "Visual Search: A Retrospective," Journal of Vision 11 (2011): 136.

radiologists, satellite image a.n.a.lysts, and fishermen: Eckstein, "Visual Search."

THE ANIMALS AMONG US.

Cooper's hawks: W. A. Estes and R. W. Mannan, "Feeding Behavior of Cooper's Hawks at Urban and Rural Nests in Southeastern Arizona," The Condor 105 (2003): 107116.

great t.i.ts: H. Slabbekoorn and M. Peet, "Birds Sing at a Higher Pitch in Urban Noise: Great t.i.ts. .h.i.t the High Notes to Ensure That Their Mating Calls Are Heard Above the City's Din," Nature 424 (2003): 267.

song sparrow: W. E. Wood and S. M. Yezerinac, "Song Sparrow (Melospiza melodia) Song Varies with Urban Noise," The Auk 123 (2006): 650659.

peppered moth: J. Alc.o.c.k, Animal Behavior, 9th ed. (Sunderland, MA: Sinauer, 2011).

"North American primate": "Racc.o.o.ns Attack in Los Angeles," interview with J. Hadidian, November 24, 2006, retrieved from http://www.npr.org/templates/story/story.php?storyId=6534152.

racc.o.o.n population numbers: J. Hadidian, S. Prange, R. Rosatte, et al., "Racc.o.o.ns (Procyon lotor), " in S. D. Gehrt, S. P. D. Riley, and B. L. Cypher, eds., Urban Carnivores: Ecology, Conflict, and Conservation (Baltimore: The Johns Hopkins Press, 2010), pp. 3547.

racc.o.o.n reaching in trash bag: Ibid.

racc.o.o.n hands: I. D. Walker, "A Successful Multifingered Hand Design-the Case of the Racc.o.o.n," in Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, 1995, 186193.

Latin name and the history: M. Pett.i.t, "The Problem of Racc.o.o.n Intelligence in Behaviourist America," British Society for the History of Science 43 (2010): 391421.

racc.o.o.n "knavery," greed: H. B. Davis, "The Racc.o.o.n: A Study in Animal Intelligence," The American Journal of Psychology 18 (1907): 447489.

Coolidge's racc.o.o.n Rebecca: "Coolidge 'c.o.o.n' Gets Ribbon and Is Now Named Rebecca," New York Times, December 25, 1926; and "Coolidge Returns to the White House from His Vacation," New York Times, September 12, 1927.

Easter egg roll: "President's Wife Attends the Easter Egg-Rolling," New York Times, April 19, 1927.

racc.o.o.ns . . . four-inch s.p.a.ce: J. Hadidian, personal communication, December 21, 2010.

starlings and Shakespeare: S. Mirsky, "Shakespeare to Blame for Introduction of European Starlings to U.S.," Scientific American (May 23, 2008).

expectation about what we will see: C. Summerfield and T. Egner, "Expectation (and Attention) in Visual Cognition," Trends in Cognitive Science 13 (2009): 403409.

inattentional blindness: D. J. Simons and C. F. Chabris, "Gorillas in Our Midst: Sustained Inattentional Blindness for Dynamic Events," Perception 28 (1999): 10591074.

"cued-target detection task": R. T. Marrocco and M. C. Davidson, "Neurochemistry of Attention," in R. Parasuraman, ed., The Attentive Brain (Cambridge, MA: MIT Press, 1998), pp. 3550.

rats' ever-growing teeth: A. F. Hanson and M. Berdoy, "Rats," in V. T. Tynes, ed., Behavior of Exotic Pets (UK: Blackwell Publishing, 2010) pp. 104116.

pigeon owl deterrents: J. Hadidian, ed., Wild Neighbors: A Humane Approach to Dealing with Wildlife (Washington D.C.: Humane Society Press, 2007).

thigmotaxic: M. R. Lamprea, F. P. Cardenas, J. Setem, and S. Morato, "Thigmotactic Responses in an Open-Field," Brazilian Journal of Medical Biological Research 41 (2008): 135140.

rat smudges: Hadidian, ed., Wild Neighbors.

rat whiskers: Hanson and Berdoy, "Rats."

rat vocalizations: Ibid.

rat play: L. W. Cole, "Observations of the Senses and Instincts of the Racc.o.o.n," Journal of Animal Behavior 2 (1912): 299309.

rat grooming: C. C. Burn, "What Is It Like to Be a Rat? Rat Sensory Perception and Its Implications for Experimental Design and Rat Welfare," Applied Animal Behaviour Science 112 (2008): 132.

rat home range: Hadidian, ed., Wild Neighbors.

rat control same since Middle Ages: Hadidian, ed., Wild Neighbors.

rat neighborhoods (Baltimore): L. C. Gardner-Santana et al., "Commensal Ecology, Urban Landscapes, and Their Influence on the Genetic Characteristics of City-Dwelling Norway Rats (Rattus norvegicus)," Molecular Ecology 18 (2009): 27662778.

rats like grids: "Rats Say: Manhattan Rules!" interview with David Eilam, Science Daily, January 13, 2009.

flock-swooping: M. Ballerini, et al. "An Empirical Study of Large, Naturally Occurring Starling Flocks: A Benchmark in Collective Animal Behaviour," Animal Behaviour 76 (2008): 201215; and H. Pomeroy and F. Heppner, "Structure of Turning in Airborne Rock Dove (Columba livia) Flocks," The Auk 109 (1992): 256267.

pigeon gliding: D. Larson, U. Matthes, P. E. Kelly, et al., The Urban Cliff Revolution: Origins and Evolution of Human Habitats (Ontario, Canada: Fitzhenry & Whiteside, 2004), p. 29.

cliffs and their ecology: D. W. Larson, U. Matthes, and P. E. Kelly, Cliff Ecology: Pattern and Process in Cliff Ecosystems (Cambridge, UK: Cambridge University Press, 2000).

"concrete and gla.s.s versions": Larson, Matthes, and Kelly, Cliff Ecology, pp. 247248.

Heat Island effect: EPA.gov: "The annual mean air temperature of a city with 1 million people or more can be 1.85.4F (13C) warmer than its surroundings. In the evening, the difference can be as high as 22F (12C)." "On a hot, sunny summer day, roof and pavement surface temperatures can be 5090F (2750C) hotter than the air." http://www.epa.gov/heatisld/index.htm.

end.