The most dangerous ant in the world is the bulldog ant (Myrmecia pyriformis) found in coastal regions in Australia. In attack it uses its sting and jaws simultaneously. There have been at least three human fatalities since 1936, the latest a Victorian farmer in 1988.
Green Tree ants, more formally known as Weaver ants, are unique in the ant world in that they form nests in trees by wrapping silk around large leaves and rolling them together into hollow balls. The nests can extend to a large number of neighbouring trees to form the colony.
Oleander (Nerium oleander) One of the most poisonous of garden plants in the world, oleander can send you into cardiac arrest within minutes of ingesting it. All of the plants parts are toxic; the leaves, flowers and fruit contain cardiac glycosides, which have therapeutic applications but are toxic if eaten in the wrong measure.
The crab’s eye “the deadly love bean” Known scientifically as Abrus precatorius and is believed to have originated from South East Asia. The seeds contain, abrin, an extremely poisonous chemical. It causes damage by attacking the body’s functions at the cellular level. When ingested whole, the rosary pea doesn't present any danger.
Caution: Water hemlock can be deadly. It contains a toxin called cicutoxin, a violent convulsant, which acts as a stimulant in the central nervous system. Ingestion of hemlock can be fatal and symptoms can occur 15 minutes to 6 hours after the plant has been ingested.