Scarcely less troublesome than the sancudos are the mosquitoes, although they have the negative merit of biting only by day. They are minute creatures, not much larger than a pin's head; they prefer the backs of the hands to any other spot for their attacks. But, unlike the sancudo, which, when undisturbed, gorges himself until unable to fly, and becomes an easy prey to your avenging finger, the mosquito never seems to take too much to prevent his easy escape on the slightest appearance of danger, being evidently just as wide-awake when full as when empty.
Everywhere in long grass lurks the "moquim," a little red insect so small as to be almost imperceptible, but which fastens on the legs, causing the most intolerable itching.
There is a fly which burrows in the skin and deposits an egg, both in human beings and animals. This produces a maggot, similar in shape to that of the common blow-fly, but much larger, probably analogous to the Guinea-worm.
Then there are "chigos," which burrow mostly in the soles of the feet. You feel an intense itching, and on examination find a little thing like a pea just under the epidermis; this is the bag containing the young chigos, which must be carefully picked out with the point of a knife, and the cavity left filled with tobacco ash.
Huge spiders abound, whose very appearance inspires a wholesome dread of a nearer acquaintance, but which are harmless enough if let alone. In fact, on board the steamers, almost every cabin is tenanted by one large spider, whose presence is tolerated on account of his being a deadly foe to cockroaches, which abominable creatures swarm on board. Sometimes he is not visible for a fortnight or more at a time; but he leaves tokens of "having been there," in the shape of the empty husks of cockroaches, from which he has carefully abstracted the interior. These spiders have the power of springing upon their prey from a distance, and some of them are so large and powerful as to kill and devour small birds.
In passing through the narrow forest paths it is necessary to be on the look-out for the wood-ticks, which are very difficult to get rid of if once firmly attached; also for the huge black ants, an inch and a half in length, with stings like a hornet's; and the saüba ant, without sting, but armed with nippers like a pair of surgical bone-forceps, which are running about everywhere. One may sometimes chance upon a column of the dreaded "fire-ants," marching in regular military order; and if he does, the only thing is to bolt at once, for neither man nor beast may withstand the fire-ant and live. When at length the traveller stops to rest, he must take care to examine the camping ground to see that neither centipede nor scorpion is there.
Frequently both centipedes and scorpions are found on the steamers, introduced, no doubt, in the wood used for fuel. One day, while the writer was watching the hands taking wood from canoes alongside, from one of the logs pitched on board was dislodged a scorpion, which fell on the naked left arm of a man keeping tally at the gangway. Astonished by his sudden flight through the air, the animal remained perfectly still. The man never moved a muscle, and quietly raising his right hand, flipped it away with his fingers and thumb. It was very neatly and coolly done; and he thus escaped a sting, which he no doubt would have received had he tried to brush it hastily away.