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.
Discus, Angelfish and Parrot Cichlids are a good combination as they are all peaceful. You could keep these together in a 75 gallon tank. Fire Eels are peaceful as well, but seeing as they grow to over 2 feet long, you then need about 100 gallons Oscars are very big, messy and aggressive sometimes.