Animal intelligence testing involves various behavioral assessments that measure learning, memory, and cognitive abilities rather than a singular definition of intelligence. Research has demonstrated that rats can count up to three through experiments using Skinner Boxes, where they learn to associate food rewards with a specific number of electrical shocks. In language comprehension, dolphins have participated in syntax experiments that test their ability to respond to complex command sequences, indicating a level of understanding similar to language use. Additionally, some chimpanzees have been involved in math experiments using symbols to communicate numerical concepts. Other studies utilize startle responses to gauge an animal's ability to differentiate quantities, akin to tests designed for pre-verbal human infants. This area of research is extensive and multifaceted, reflecting a growing interest in understanding animal cognition.