while pregnant, and two out of three females have been observed to engage in sexual behavior while lactating. Females are significantly more likely to engage and participate in sexual behavior and activity on a day when another female is sexually active. It has been found that female western lowland gorillas participate in non-reproductive sexual behavior in order to increase their reproductive success through sexual competition. By increasing the female’s own reproductive success, she then decreases the reproductive success of other female gorillas, regardless of their reproductive state. Infanticide by adult male gorillas has occasionally been observed in this subspecies. Victims are never related to the killer. A male does this in order to have the opportunity to mate with the mother, who otherwise would be unavailable while caring for her young offspring. Intelligence Use of tools Their intelligence is displayed through their ability to fashion natural materials into tools that help them gather food more conveniently. While the use and manufacture of tools to extract ants and termites is a well-documented behavior in wild chimpanzees, it has never been observed in other great apes in their natural habitat and never seen to be done by other primates in captivity. In terms of manufacturing tools for the use of extracting for western lowland gorillas, they are able to adapt tools to a particular use by selecting branches, removing projections such as leaves and bark and adapting their length to the depth of the holes. It appears that they also anticipate the use of the tool since they begin with the biggest sticks available and progressively modify it until it is the perfect fit for inserting into a hole that contains food. This demonstrates the gorillas' acquisition of high level sensorimotor intelligence, similar to that of young human children. In the past, there was a gorilla that used a stick to measure the depth of water. In 2009, a western lowland gorilla at Buffalo Zoological Gardens used a bucket to collect water. In an experiment, one adult male gorilla and three adult female gorillas were given five-gallon buckets near a standing pool. Two of the younger females were able to fill the buckets with water. This is the first record of gorillas spontaneously using tools to drink in zoos. Communication Another example of gorillas' significant intelligence is their ability to comprehend simple sign language. In the mid-1970s, researchers turned their attention to