All substances take up the least amount of volume in their (1.) solid phase, a little more volume in their (2.) liquid phase, and the largest amount of volume in their (3.) gas phase. The closer atoms or molecules get to one another, the less volume is occupied by the substance that they comprise.
A large, retrospective series examining human bite wounds in children found that none of the bites manifesting as abrasions became infected, while the rate of infection was much higher in bite wounds that caused punctures or lacerations.
While usually very gentle and will not harm humans, a wolf spider may bite if it feels threatened, startled, or thinks that its young are in danger. A wolf spider bite is very uncomfortable to very painful depending on which specific wolf spider has taken the bite.