The US sensors are present in the antennae of Mosquitoes and genetalia of Cockroaches. US emitted by the Repeller will scare away the pests and confuse them. Ultrasonic sound will create stress on the nervous system of insects and jam their own US frequency.
South America also houses several larger river cichlids. These species will often get along well in aquariums. For example, various species of freshwater angelfish and the discus fish make great tank mates.Both species prefer soft, acidic water and, importantly, grow to about the same size.frican cichlids prefer hard, alkaline water. Most are very aggressive, but in a large tank, dissimilar-patterned species can get along. You do want to avoid keeping closely related species together, since they may produce undesirable hybrids. For example, no two Auloncara species should share an aquarium.
The graceful angelfish are considered one of the most docile cichlids. Despite most cichlids being highly aggressive fish in an aquarium community, several species of cichlids are calmer and more docile. Angelfish, for instance, are among the most docile of all cichlid species.A few other species of cichlids can live peacefully with their angelfish cousins.ichlids and Aggression. Many cichlids are aggressive because of their natural environment -- the waters these fish live in are teeming with predators and competitors. As such, in their natural environment they are supremely territorial; this behavior carries into their aquarium environment.