arachnid: A group of invertebrate animals that includes spiders, scorpions, mites and ticks. Many have silk or venom glands.
biologist: A scientist involved in the study of living things.
chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.
chemical signal: A message made up of molecules that get sent from one place to another. Bacteria and some animals use these signals to communicate.
glare: Also called direct glare, it is light that travels directly from a light source and into someone’s eyes. It reduces the ability to see at night. Direct glare is one of three types of light pollution.
navigate: To find one’s way through a landscape using visual cues, sensory information (like scents), magnetic information (like an internal compass) or other techniques.
species: A group of similar organisms capable of producing offspring that can survive and reproduce.
spider: A type of arthropod with four pairs of legs that usually spin threads of silk that they can use to create webs or other structures.
surface tension: The surface film of a liquid caused by the strong bonds between the molecules in the surface layer.
wave: A disturbance or variation that travels through space and matter in a regular, oscillating fashion.
zoology: The study of animals and their habitats. Scientists who undertake this work are known as zoologists.
